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  • 151.
    Helgadottir, Björg
    et al.
    PHS, EPHIR Karolinska Institutet.
    Forsell, Yvonne
    PHS, EPHIR Karolinska Institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Physical activity patterns of people affected by depressive and anxiety disorders as measured by accelerometers: a cross-sectional study2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 1, p. e0115894-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    Exercise can relieve both depressive and anxiety disorders and it is therefore of importance to establish movement patterns of mildly to moderately affected sufferers to estimate the treatment potential. The aim is to describe the physical activity patterns of people affected by mild to moderate depressive and/or anxiety symptoms using objective measures of physical activity.

    METHODS:

    The design of the study was cross-sectional using data from 165 people aged 18-65 years, with mild to moderate depressive and/or anxiety disorder symptoms (scoring ≥10 on the PHQ-9). Diagnoses were made using Mini International Neuropsychiatric Interview (MINI) and symptom severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). The participants wore accelerometers for a week to evaluate physical activity patterns.

    RESULTS:

    No statistically significant differences were detected between different diagnoses, though depressed participants tended to be less active and more sedentary. Only one-fifth of the sample followed public health guidelines regarding physical activity. Each one point increase in MADRS was associated with a 2.4 minute reduction in light physical activity, independent of moderate-to-vigorous physical activity and sedentary time. MADRS was positively associated with number of sedentary bouts.

    CONCLUSIONS:

    The physical activity pattern of people with depressive and/or anxiety disorders was characterized by large amounts of sedentary time and low fulfillment of physical activity guidelines. There is therefore a large treatment potential for this group by increasing exercise. The results suggest that instead of focusing exclusively on high intensity exercise for treating depressive and anxiety disorders, health care providers might encourage patients to reduce sedentary time by increasing light physical activity and decreasing the number of sedentary bouts, though further studies are needed that can determine directionality.

  • 152. Helgadóttir, Björg
    et al.
    Dunstan, David
    Owen, Neville
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Hallgren, Mats
    Forsell, Yvonne
    Changes in Physical Activity and Sedentary Behavior Associated with Exercise Interventions in Depressed Adults: 2109 Board #261 June 2, 3: 30 PM - 5: 00 PM.2016In: Medicine And Science In Sports And Exercise 2016 May; Vol. 48 (5S Suppl 1), pp. 594., 2016, Vol. 48, no 5S Suppl 1, p. 594-594Conference paper (Refereed)
    Abstract [en]

    PURPOSE: Exercise training programs are beneficial for depression, but less is known about their impact on non-intervention physical activity patterns and sedentary behavior patterns in depressed adults. We determined the extent to which participation in light-, moderate- and vigorous-intensity exercise intervention programs influenced the habitual physical activity and sedentary behavior patterns in depressed adults.

    METHODS: Accelerometer data were collected pre- and post-treatment from a subset of depressed participants randomized to one of three 12-week exercise intervention programs: light (n=21), moderate (n=25) and vigorous (n=22) exercise. Mixed models examined changes in accelerometer-measured overall time spent in sedentary, light and moderate-to-vigorous physical activity (MVPA); accumulated sedentary and MVPA bouts; and number of MVPA bouts and interruptions in sedentary time.

    RESULTS: Overall sedentary time decreased while overall light activity increased across all intervention groups but neither significantly so. The light exercise intervention group reduced their MVPA minutes (-8.22, 95% CI: -16.44, -0.01), time in MVPA bouts (-8.44, 95% CI: -14.27, -2.62), and number of activity bouts (-0.43, 95% CI: -0.77, -0.09). The moderate exercise intervention group reduced the time in MVPA bouts (-6.27, 95% CI: -11.71, -0.82) and number of sedentary interruptions (-5.79, 95% CI: -9.11, -2.46). No changes were observed for the vigorous exercise intervention group.

    CONCLUSIONS: On the whole, participating in a structured exercise intervention did not lead people who are affected by depression to significantly reduce their overall light physical activity nor to increase their sedentary time. Participation in the light and moderate exercise intervention programs was associated with reductions in overall MVPA, but this was not evident for the vigorous exercise intervention program.

  • 153.
    Helgadóttir, Björg
    et al.
    Karolinska institutet.
    Forsell, Y
    Karolinska institutet.
    Hallgren, M
    Karolinska institutet.
    Möller, J
    Karolinska institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Exercise for depression: What are the long-term effects of different exercise intensities?2017In: European Journal of Public Health, Volume 27, Issue suppl_3, 1 November 2017, 2017, Vol. 27, no Suppl. 3, article id ckx187.168Conference paper (Refereed)
    Abstract [en]

    Key messages:

    • As all exercise conditions had at least a comparable effect to treatment as usual, exercise at any intensity can be recommended as treatment for mild-to-moderate depression.
    • Light intensity exercise should be emphasised more in treatment guidelines than it currently is, as its effects are potentially even greater than that of treatment as usual.
  • 154.
    Helgadóttir, Björg
    et al.
    Karolinska Institutet, Stockholm, Sweden.
    Forsell, Yvonne
    Karolinska Institutet, Stockholm, Sweden.
    Hallgren, Mats
    Karolinska Institutet, Stockholm, Sweden.
    Möller, Jette
    Karolinska Institutet, Stockholm, Sweden.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Long-term effects of exercise at different intensity levels on depression: A randomized controlled trial.2017In: Preventive Medicine, ISSN 0091-7435, E-ISSN 1096-0260, Vol. 105, p. 37-46, article id S0091-7435(17)30294-3Article in journal (Refereed)
    Abstract [en]

    Previous research has shown positive effects of exercise on depression but studies have mainly focused on the short-term effects; few have examined the long-term effect, especially with regard to differences in intensity. The aim of this study was to examine the long-term effects of prescribed exercise on depression, performed at three intensity levels. People aged 18-67years with mild to moderate depression (Patient Health Questionnaire-9 score of ≥10) participated in a single-blind, parallel randomized control trial lasting 12weeks (Sweden 2011-2013). Four arms were included: Treatment as usual (TAU, n=310), light (n=106), moderate (n=105) and vigorous exercise (n=99). Severity of depression was measured at baseline, post-treatment and 12-month follow-up using the Montgomery-Åsberg Depression Rating Scale (MADRS). Coefficients (β) and odds ratios were estimated using linear mixed models with time×group interactions. The results showed that at the 12month follow-up the light exercise group had significantly lower depression severity scores than the TAU (-1.9, 95% CI: -3.7, -0.04) and the moderate exercise group (-2.94 95% CI: -5.2, -0.7). The vigorous exercise group had significantly lower scores than the moderate exercise group only (-2.7, 95% CI: -4.9, -0.4). In conclusion, compared to usual care for depression, only light exercise resulted in significantly lower depression severity at 12-month follow-up. Both light and vigorous exercise was more effective than moderate exercise.

    TRIAL REGISTRATION: The study was registered with the German Clinical Trial Register (DRKS study ID: DRKS00008745).

  • 155. Helgadóttir, Björg
    et al.
    Owen, Neville
    Dunstan, David W.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hallgren, Mats
    Forsell, Yvonne
    Changes in physical activity and sedentary behavior associated with an exercise intervention in depressed adults2017In: Psychology of Sport And Exercise, ISSN 1469-0292, E-ISSN 1878-5476, Vol. 30, p. 10-18Article in journal (Refereed)
    Abstract [en]

    Background Exercise is beneficial for depression, but less is known about its impact on post-intervention physical activity and sedentary behavior. The aim of this paper was to determine the extent to which participation in light-, moderate- and vigorous-intensity exercise intervention influenced habitual physical activity and sedentary behavior patterns in depressed adults. Methods Accelerometer data was collected pre- and post-intervention from depressed participants randomized to one of three 12-week intervention groups: light (n = 21), moderate (n = 25) and vigorous (n = 22) exercise. Mixed models examined changes in time spent sedentary and in light and moderate-to-vigorous physical activity (MVPA); time accumulated in sedentary and MVPA bouts; and, number of MVPA bouts and interruptions in sedentary time. Results Overall sedentary time decreased while light activity time increased across all intervention groups but not significantly so. The light exercise intervention group reduced MVPA minutes (−8.22, 95% CI: −16.44, −0.01), time in MVPA bouts (−8.44, 95% CI: −14.27, −2.62), and number of activity bouts (−0.43, 95% CI: −0.77, −0.09). The moderate exercise intervention group reduced time in MVPA bouts (−6.27, 95% CI: −11.71, −0.82) and number of sedentary interruptions (−6.07, 95% CI: −9.30, −2.84). No changes were observed for the vigorous exercise intervention group. Conclusions The exercise intervention led to an increase in overall light physical activity and decrease in sedentary time, though neither change was statistically significant. Participation in the light and moderate exercise intervention groups was associated with reductions of time in MVPA bouts, but this was not evident for the vigorous exercise intervention group.

  • 156.
    Hellénius, Mai-Lis
    et al.
    Karolinska institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Epidemiologi och mekanismer2013In: Långvarigt stillasittande: en hälsofara i tiden / [ed] Elin Ekblom Bak, Studentlitteratur, 2013, p. 19-45Chapter in book (Other academic)
  • 157. Hendo, Gina
    et al.
    Jakobsson, Madeleine
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Slutövning GMU: "Aldrig ge upp", Amf1, Berga örlogsbas: Muskelfysiologiska resultat2014Report (Other academic)
    Abstract [sv]

    Energistatus, muskelfysiologiska data och fysiskt stridsvärde studerades före och efter en 8 dygn långa grundmilitär slutövning (GMU) vid AMF-1 Berga Örlogsskolor i månadsskiftet oktober november 2013.

    Totalt deltog 105 soldater i övningen, fördelat på 3 plutoner om vardera 35 soldater. En subgrupp på 24 soldater (8 kvinnor) bestående av 8 soldater från vardera pluton studerades mer ingående.

    Medelhjärtfrekvensen för de 6 soldater (2 kvinnor) som hade i stort sett kompletta mätningar från den 187 timmar långa övningen, inklusive viloperioder, var 88 ± 7 slag/minut. Utifrån hjärtfrekvensdata beräknades den totala energiomsättningen till i genomsnitt 44 000 ± 6 600 kcal, vilket motsvarar 5 600 ± 840 kcal per dygn och 235 ± 35 kcal/tim. Total energiförbrukning var i genomsnitt 39 000 kcal för kvinnorna och 46 500 kcal för männen. I övrigt noterades inte några betydande skillnader mellan kvinnor och män. Däremot var det stora individuella variationer i energiutgift, vilka till ca hälften berodde på skillnader i kroppsvikt. Med hänsyn till kroppsvikt och buren vikt var energiförbrukningen ca 3,1 ± 0,23 kcal per timme per kg totalvikt. Den individuella variationen beror på skillnad i buren vikt, på olika uppgifter och på individuella fysiologiska skillnader.

    Utifrån beräknat energiintag blev det totala energiunderskottet under övningen 12 000-15 000 kcal, vilket är ca 1 500-2 000 kcal per dygn. Viktminskningen under övningen var 2,9 kg för kvinnor och 3,7 kg för män. Denna viktminskning på >4 % leder troligen till försämrad uthållighetsförmåga.

    Den maximala muskelstyrkan i armar och ben var i stort sett oförändrade efter övningen, liksom den beräknade maximala syreupptagningsförmågan. Däremot upplevdes ett lågintensivt cykelarbete som betydligt tyngre efter övningen. Muskeluthållighet mättes inte i denna studie.

    Ett skjutprov om 5 skott i liggande på 100 m mot en tredjedelsfigur visade 64 deltagande soldater på en försämrad träffprocent från 90,5% före till 79,4 % efter övningen. Alla soldater hade minst en träff före medan 6 soldater hade alla bom efter övningen.

    Slutsatsen från studien är att GMU-övningen resulterade i ett stort energiunderskott. Stridsvärdet, bedömt från skjutprovet var klart försämrat. Maximala fysiologiska parametrar var i stort sett oförändrade, medan skattad ansträngning och därmed uthållighetsförmåga, försämrades.

  • 158.
    Holmberg, H-C
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Svedenhag, J
    Lung function, arterial saturation and oxygen uptake in elite cross country skiers: influence of exercise mode.2007In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 17, no 4, p. 437-44Article in journal (Refereed)
    Abstract [en]

    Arterial desaturation during exercise is common in endurance-trained athletes, a phenomenon often more pronounced when the muscle mass engaged in the exercise is large. With this background, the present study monitored seven international-level cross country skiers performing on a treadmill while running (RUN), double poling (DP; upper body exercise) and diagonal skiing (DIA; arm and leg exercise). Static and dynamic lung function tests were performed and oxygen uptake was measured during submaximal and maximal exercise. Lung function variables (including the diffusion capacity) were only 5-20% higher than reported in sedentary men. Vital capacity was considerably lower than expected from the skiers' maximal oxygen uptake (VO(2max)), but the maximal ventilation followed a linear relationship with VO(2max). None or only a mild desaturation was observed in DP, RUN and DIA. Blood lactate concentration was slightly higher in DIA than in DP but not different from RUN. In DIA, VO(2max) was 6.23 +/- 0.47 L/min (mean +/- SD), which was 3.8% and 13.9% higher than in RUN and DP, respectively, with similar peak heart rates for the three exercise modes. No relationships were present either between the degree of desaturation and pulmonary functions tests, or with peak oxygen uptakes. The low blood lactate accumulation during the exhaustive efforts contributed to the arterial oxygen saturation being mild in spite of the very high oxygen uptake observed in these skiers.

  • 159.
    Holmlund, Tobias
    et al.
    Karolinska institutet.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Franzén, Erika
    Karolinska institutet.
    Hultling, Claes
    Karolinska institutet.
    Wahman, Kerstin
    Karolinska institutet.
    Energy expenditure after spinal cord injury in people with motor-complete tetraplegia or motor-complete paraplegia.2018In: Spinal Cord, ISSN 1362-4393, E-ISSN 1476-5624, Vol. 56, no 3, p. 274-283Article in journal (Refereed)
    Abstract [en]

    STUDY DESIGN: Cross-sectional.

    OBJECTIVES: This study aimed to describe and compare VO2 and energy expenditure at rest (REE) and during standardized sedentary, non-exercise physical activity, and exercise activities, in people with motor-complete tetraplegia (C5-C8). Further, REE and energy expenditure (EE) for the different activities were compared to data from a reference group of people with motor-complete paraplegia (T7-T12).

    SETTING: Sweden.

    METHODS: The sample of people with motor-complete tetraplegia consisted of 26 adults (seven women) with SCI, C5-C8 AIS A-B. REE and EE for the different activities were measured with indirect calorimetry. The results were further compared to people with motor-complete paraplegia.

    RESULTS: Resting VO2 was 2.57 ml O2 kg-1 min-1, 2.54 for men and 2.60 for women. The VO2 or activity energy expenditure related to body weight increased three to four times during non-exercise physical activity compared to sedentary activities for the people with motor-complete tetraplegia, and up to six times during exercise activity. No significant differences were seen in resting or sedentary activity VO2 between the people with motor-complete tetraplegia and those with motor-complete paraplegia. Activities of daily life revealed no or small differences in VO2, except for setting a table, while the people with tetraplegia had ∼50% lower VO2 during exercise activities.

    CONCLUSIONS: Non-exercise physical activities of daily life may be significant for increasing total daily EE in people with motor-complete tetraplegia. This might act to motivate the individual, and might be clinically important when designing adapted lifestyle intervention programs for the target group.

  • 160.
    Holmlund, Tobias
    et al.
    Karolinska institutet.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Franzén, E
    Karolinska institutet.
    Hultling, C
    Karolinska institutet.
    Wikmar, L Nilsson
    Karolinska institutet.
    Wahman, K
    Karolinska institutet.
    Energy expenditure in people with motor-complete paraplegia.2017In: Spinal Cord, ISSN 1362-4393, E-ISSN 1476-5624, Vol. 55, no 8, p. 774-781Article in journal (Refereed)
    Abstract [en]

    STUDY DESIGN: The present descriptive clinical and laboratory study is cross-sectional in design.

    OBJECTIVES: The primary aim is to describe and compare resting energy expenditure (REE) and energy expenditure (EE) during different standardized sedentary, non-exercise and exercise activities in people with motor-complete paraplegia (Th7 to Th12.). A secondary aim was to compare men and women.

    METHODS: Thirty-eight adults (10 women) with SCI, T7-T12 AIS A-B, were recruited. All the data were collected through indirect calorimetry. REE was measured in supine for 30 min after 8 h of overnight fasting. Activity energy expenditure (AEE) for activities was measured for seven minutes during sedentary, non-exercise physical activity (NEPA) and exercise activities.

    RESULTS: AEE increased four to eight times when engaging in NEPA compared to that in sedentary activities. Men had significantly higher resting oxygen uptake compared to women, 0.19 vs 0.15 l min(-1) (P=0.005), REE per 24 h, 1286 vs 1030 kcal (P=0.003) and EE during weight-bearing activities. However, these became nonsignificant after adjustment for body weight and speed of movement, with a mean resting oxygen uptake of 2.47 ml O2 per kg min(-1) for the whole group (women 2.43 and men 2.57 ml O2 kg(-1) min(-1), P=0.49).

    CONCLUSIONS: NEPA increases AEE up to eight times compared to sedentary activities. Gender differences in oxygen uptake during both rest and weight-bearing activities were diminished after adjustment for body weight. The mean resting oxygen uptake for the whole group was 2.47 ml O2 kg(-1) min(-1). These results highlight the importance, especially of NEPA, for increasing total daily EE in the target population.

  • 161. Johnson, Urban
    et al.
    Ivarsson, Andreas
    Karlsson, Jón
    Hägglund, Martin
    Waldén, Markus
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Rehabilitation after first-time anterior cruciate ligament injury and reconstruction in female football players: a study of resilience factors.2016In: BMC Sports Science, Medicine And Rehabilitation, ISSN 2052-1847, Vol. 8, article id 20Article in journal (Refereed)
    Abstract [en]

    Background: Most of the research in the area of psychosocial factors in rehabilitation after sports injuries has focused on risk behaviors, while relatively few studies have focused on behaviors that facilitate rehabilitation. The objective of our study was to understand the psychosocial features that characterize elite female football players who express a resilient behaviour during rehabilitation after a first-time anterior cruciate ligament (ACL) injury and reconstruction.; Methods: A qualitative method was used based on individual in-person interviews and video communication of players who incurred a first-time ACL tear during the 2012 season of the Swedish Women's Elite Football League. In total, 13 players had a first-time ACL and were interviewed post-season. The interviews were followed by a thematic content analysis. Based on this, eight players were identified as showing resilient behaviors during their rehabilitation and were included in the final analysis.; Results: Three core themes representing psychosocial factors that help players cope successfully with rehabilitation were identified: (I) constructive communication and rich interaction with significant others; (II) strong belief in the importance and efficacy of one's own actions; and (III) the ability to set reasonable goals.; Conclusions: The findings suggest three core themes of psychosocial factors that characterize first-time ACL-injured elite female football players showing resilience during rehabilitation after ACL reconstruction. Suggestions for medical teams about ways to support communication, self-efficacy, and goal-setting during the rehabilitation process, are provided.;

  • 162.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hur ska vi fråga om fysisk aktivitet?2016In: Idrottsmedicin, ISSN 2001-3302, Vol. 35, no 3, p. 20-23Article in journal (Other academic)
  • 163.
    Kallings, Lena V
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    The organisation of promoting physical activity in health care – examples from the Nordic countries.2016In: Clinical Health Promotion - research and best practice for patients, staff and community., ISSN 2226-5864, Vol. 6, no Suppl 2, p. 27-30Article in journal (Other academic)
  • 164.
    Kallings, Lena V
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    The Swedish approach on physical activity on prescription2016In: Clinical Health Promotion - research and best practice for patients, staff and community, ISSN 2226-5864, Vol. 6, no Suppl 2, p. 31-33Article in journal (Other academic)
  • 165.
    Kallings, Lena V
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Hellénius, M-L
    Karolinska Institutet.
    Physical activity on prescription reduces sedentary behaviour for 6 months, without long term effect2014Conference paper (Refereed)
    Abstract [en]

    Objectives

    There is a lack of knowledge regarding methods to reduce sedentary behaviour. The aim of this study was to evaluate the efficacy of physical activity on prescription (PAP) in patients with overweight and abdominal obesity. PAP decrease sitting time at 6-months follow-up in this population, and data is now further analysed to study the longterm effect.

    Methods

    Six month randomised controlled study in 101 women and men (57% female, 67-68 year). All participants received a minimal intervention with brief general information on physical activity and measurement of PAL. The intervention group received in addition an individualized PAP that consisted of a patient centred counselling and a written agreement. Focus of the intervention was to reduce sedentary behaviour as well as to promote an increased PAL. Sedentary behaviour was assessed by questionnaire, the sitting item from IPAQ.

    Results

    Both groups reduced sitting time from baseline to 6-months follow-up, intervention group by 114 min/day and control group by 86 min/day. However, the changes disappeared at the long term follow-ups (Figure). There were no significant differences between the groups at either time point.

    Conclusions

    It is possible to reduce sitting time in overweight individuals. An individualized prescription of physical activity reduces sedentary behaviour for 6 months, but had no long term effects. There was no significant better effect of PAP compared to a minimal intervention. Studies with more subjects and objective methods are needed.

  • 166. Kalsen, Anders
    et al.
    Hostrup, Morten
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Karlsson, Sebastian
    Backer, Vibeke
    Bangsbo, Jens
    Inhaled Beta2-agonist Increases Power Output and Glycolysis during Sprinting in Men.2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 1, p. 39-48Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The aim of the present study was to investigate the effect of the beta2-agonist terbutaline (TER) on power output and muscle metabolism during maximal sprint cycling.

    METHODS: In a randomized double-blind crossover design, nine moderately trained men (VO2max: 4.6±0.2 L[BULLET OPERATOR]min) conducted a 10-s cycle sprint after inhalation of either 15 mg TER or placebo (PLA). A muscle biopsy was collected before and <10 s after the sprint, and analyzed for metabolites.

    RESULTS: Mean and peak power during the sprint were 8.3±1.1 and 7.8±2.5 % higher (P<0.05) in TER than in PLA, respectively. Moreover, net rate of glycogenolysis (6.5±0.8 vs. 3.1±0.7 mmol glucosyl units kg dw s) and glycolysis (2.4±0.2 vs. 1.6±0.2 mmol glucosyl units kg dw s) were higher (P<0.05) in TER than in PLA. After the sprint, ATP was reduced in PLA (P<0.05), but not in TER. During the sprint, there was no difference in breakdown of phosphocreatine (PCr) between treatments. Estimated anaerobic ATP utilization was 9.2 ±4.0 % higher (P<0.05) in TER than in PLA. After the sprint, ATP was lowered (P <0.05) by 25.7±7.3 % in type II fibers in PLA with no reduction in TER. Before the sprint, PCr was 24.5±7.2 % lower (P <0.05) in type II fibers in TER than in PLA. In PLA, breakdown of PCr was 50.2±24.8 % higher (P <0.05) in type II than in type I fibers with no difference in TER.

    CONCLUSION: The present study shows that a terbutaline-induced increase in power output is associated with increased rates of glycogenolysis and glycolysis in skeletal muscles. Furthermore, as terbutaline counteracted a reduction in ATP in type II fibers, terbutaline may postpone fatigue development in these fibers.

  • 167.
    Khalaf, Atika
    et al.
    Högskolan i Kristianstad.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Kowalski, Jan
    Berggren, Vanja
    Karolinska Institutet.
    Westergren, Albert
    Högskolan i Kristianstad.
    al-Hazzaa, Hazzaa
    College of Education and Obesity Research Chair, King Saud University, Saudi Arabia.
    Female University Students’ Physical Activity Levels and Associated Factors — A Cross-Sectional Study in Southwestern Saudi Arabia2013In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 10, no 8, p. 3502-3517Article in journal (Refereed)
    Abstract [en]

    Background: The high prevalence of physical inactivity in Saudi Arabia is a growing challenge to public health. This study aimed to examine the prevalence of physical activity (PA) and associated factors among female university students. Methods: This cross-sectional study involved 663 randomly selected female university students who completed the Arab Teens Life Style questionnaire. Data included measurements of anthropometric, socioeconomic and environmental factors, as well as self-reported PA. Ordinal regression was used to identify associated factors with low, moderate and high PA levels.Results: The mean age of participants was 20.4 years (SD 1.5). Mean BMI of the students in relation to PA were 23.0, 22.9, 22.1 for high, moderate and low levels of activity, respectively. The analysis revealed significantly higher PA levels among married students, those with high educated mothers, and those who lived far from parks, and lower activity levels among underweight students. Conclusions: This study raises four important determinants for female university students’ PA levels. These factors could be of great importance in the endeavor to prevent the health-threatening increase in physical inactivity patterns and thus non-communicable diseases and obesity where the focus should be on the specific situation and needs of women in Saudi Arabia.

  • 168. Khalaf, Atika
    et al.
    Westergren, Albert
    Berggren, Vanja
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M.
    Perceived and Ideal Body Image in Young Women in South Western Saudi Arabia.2015In: Journal of Obesity, ISSN 2090-0708, E-ISSN 2090-0716, article id 697163Article in journal (Refereed)
    Abstract [en]

    Objectives. The aim of this study was to investigate perceived and ideal body image (BI) and associated factors among female university students in Saudi Arabia. Methods. This cross-sectional study included 663 university female students. Anthropometric measurements including weight, height, BMI, and BI perception (the 9-figure silhouette) were obtained. Descriptive and logistic regression analysis were conducted. Results. An agreement between actual, perceived, and ideal BI was found in 23% of the participants. Behavioral (activity levels), social (presence of obese parents and fathers’ level of education), and economic factors (households’ monthly income, number of cars in the household, and kind of residence) were positively and significantly associated with the desire to be thinner. Similarly, socioeconomic associations (number of sisters and number of cars in the household) correlated positively and significantly with the desire to be heavier. Conclusions. The whole family should rather be considered in interventions related to appearance concerns and BI discrepancies. Furthermore, campaigns targeting improvement of adolescents’ physical self-image should be a major priority of the public health sector. [ABSTRACT FROM AUTHOR]

  • 169. Khalaf, Atika
    et al.
    Westergren, Albert
    Berggren, Vanja
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M
    Prevalence and association of female weight status and dietary habits with sociodemographic factors: a cross-sectional study in Saudi Arabia.2015In: Public Health Nutrition, ISSN 1368-9800, E-ISSN 1475-2727, Vol. 18, no 5, p. 784-796Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Research about the prevalence of underweight and overweight/obesity in the Saudi Arabian female population is limited. The aim of the present study was to examine the dietary habits and the prevalence of underweight and overweight/obesity and associated factors among female university students.

    DESIGN: A cross-sectional study.

    SETTING: A university centre for female students in south-western Saudi Arabia.

    SUBJECTS: The study involved 663 randomly selected female university students who self-reported their physical activities, nutritional habits and socio-economic factors. Multiple linear and logistic regression analyses were used to identify factors associated with the students' BMI, dietary variables, underweight and overweight/obesity.

    RESULTS: The majority of the university females were normal weight (56·9 %), but a high prevalence of underweight (19·2 %) and overweight/obesity (23·8 %) occurred. Social factors significantly associated with BMI were the presence of obese parents and siblings as well as physical activity levels, marital status, number of sisters, father's level of education and more frequent intake of French fries/potato chips (>3 times/week). Several variables were found to correlate with dietary habits, underweight and overweight/obesity. Of special interest is the association between the number of siblings and the participants' BMI and dietary intake in both negative and positive ways.

    CONCLUSIONS: The findings of this research have implications for health promotion and prevention of malnutrition among college-aged females. Health-care providers and policy makers need to involve the whole family when promoting females' physical activity. The study serves as an evidence-based background for planning and implementation of interventions targeting improvement of highly educated populations' nutritional habits.

  • 170. Khalaf, Atika
    et al.
    Westergren, Albert
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M
    Berggren, Vanja
    Nurses' views and experiences of caring for malnourished patients in surgical settings in Saudi Arabia - a qualitative study.2014In: BMC Nursing, ISSN 1472-6955, E-ISSN 1472-6955, Vol. 13, p. 29-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Although the occurrence of malnutrition in hospitals is a growing concern, little is known about how hospital staff understand the care that nurses provide to patients with malnutrition. The purpose of this study was to explore nurses' views and experiences of caring for malnourished patients in Saudi Arabia (KSA).

    METHODS: Using a qualitative explorative design, fifteen nurses were interviewed as part of a purposive sample hospital staff. The transcripts were analyzed using latent content analysis.

    RESULTS: The nurses spontaneously and consistently linked malnutrition with physical inactivity. The two main categories, which emerged, were: 'Potentials for nurses to provide good nutrition and physical activity', and 'Having the ability but not the power to promote proper nutrition and physical activity'. These arose from the subcategories: Good nursing implies providing appropriate health education; Acknowledging the Mourafiq (sitter) as a potential resource for the nursing, but also as a burden; Inadequate control and lack of influence; Cultural diversity and lack of dialog; and Views of women's weight gain in KSA society.

    CONCLUSIONS: The nurses felt they have the capacity and passion to further improve the nutrition and activity of their patients, but obstacles in the health care system are impeding these ambitions. The implications for nursing practice could be acknowledgement of the nurses' views in the clinical practice; culturally adjusted care, improved communication and enhanced language skills.

  • 171.
    Krustrup, Peter
    et al.
    Inst of exercise and sport sciences dept of human physiology, August Krogh inst, University of Copenhagen .
    Secher, Niels H
    Relu, Mihai U
    Hellsten, Ylva
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bangsbo, Jens
    Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans.2008In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 586, no Pt 24, p. 6037-48Article in journal (Refereed)
    Abstract [en]

    We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P < 0.05) by 28% in FT fibres, whereas in CON, CP decreased (P < 0.05) by 33% and 23% in ST and FT fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P < 0.05) in CUR compared to CON (425 +/- 25 (+/- S.E.M.) versus 332 +/- 30 ml min(-1)) and remained higher (P < 0.05) throughout exercise. Using monoexponential fitting, the time constant of the exercise-induced muscle VO2 response was slower (P < 0.05) in CUR than in CON (55 +/- 6 versus 33 +/- 5 s). During CUR and CON, muscle homogenate CP was lowered (P < 0.05) by 32 and 35%, respectively, and also muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P < 0.05) in CUR than in CON (1196 +/- 90 versus 1011 +/- 59 mmol) and true mechanical efficiency was lower (P < 0.05) in CUR than in CON (26.2 +/- 2.0 versus 30.9 +/- 1.5%). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

  • 172. Krustrup, Peter
    et al.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mohr, Magni
    Bangsbo, Jens
    Slow-twitch fiber glycogen depletion elevates moderate-exercise fast-twitch fiber activity and O2 uptake.2004In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 36, no 6, p. 973-82Article in journal (Refereed)
    Abstract [en]

    PURPOSE: We tested the hypotheses that previous glycogen depletion of slow-twitch (ST) fibers enhances recruitment of fast-twitch (FT) fibers, elevates energy requirement, and results in a slow component of VO2 during moderate-intensity dynamic exercise in humans. METHODS: Twelve healthy, male subjects cycled for 20 min at approximately 50% VO2max with normal glycogen stores (CON) and with exercise-induced glycogen depleted ST fibers (CHO-DEP). Pulmonary VO2 was measured continuously and single fiber, muscle homogenate, and blood metabolites were determined repeatedly during each trial. RESULTS: ST fiber glycogen content decreased (P < 0.05) during CON (293 +/- 24 to 204 +/- 17 mmol x kg d.w.), but not during CHO-DEP (92 +/- 22 and 84 +/- 13 mmol x kg d.w.). FT fiber CP and glycogen levels were unaltered during CON, whereas FT fiber CP levels decreased (29 +/- 7%, P < 0.05) during CHO-DEP and glycogen content tended to decrease (32 +/- 14%, P = 0.07). During CHO-DEP, VO2 was higher (P < 0.05) from 2 to 20 min than in CON (0-20 min:7 +/- 1%). Muscle lactate, pH and temperature, ventilation, and plasma epinephrine were not different between trials. From 3 to 20 min of CHO-DEP, VO2 increased (P <0.05) by 5 +/- 1% from 1.95 +/- 0.05 to 2.06 +/- 0.08 L x min but was unchanged during CON. In this exercise period, muscle pH and blood lactate were unaltered in both trials. Exponential modeling revealed a slow component of VO2 equivalent to 0.12 +/- 0.04 L x min during CHO-DEP. CONCLUSION: This study demonstrates that previous glycogen depletion of ST fibers enhances FT fiber recruitment, elevates O2 cost, and causes a slow component of VO2 during dynamic exercise with no blood lactate accumulation or muscular acidosis. These findings suggest that FT fiber recruitment elevates energy requirement of dynamic exercise in humans and support an important role of active FT fibers in producing the slow component of VO2

  • 173.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Effects of dietary nitrate on oxygen cost during exercise2007In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, no 1, p. 59-66Article in journal (Refereed)
    Abstract [en]

    AIM: Nitric oxide (NO), synthesized from l-arginine by NO synthases, plays a role in adaptation to physical exercise by modulating blood flow, muscular contraction and glucose uptake and in the control of cellular respiration. Recent studies show that NO can be formed in vivo also from the reduction of inorganic nitrate (NO(3) (-)) and nitrite (NO(2) (-)). The diet constitutes a major source of nitrate, and vegetables are particularly rich in this anion. The aim of this study was to investigate if dietary nitrate had any effect on metabolic and circulatory parameters during exercise. METHOD: In a randomized double-blind placebo-controlled crossover study, we tested the effect of dietary nitrate on physiological and metabolic parameters during exercise. Nine healthy young well-trained men performed submaximal and maximal work tests on a cycle ergometer after two separate 3-day periods of dietary supplementation with sodium nitrate (0.1 mmol kg(-1) day-1) or an equal amount of sodium chloride (placebo). RESULTS: The oxygen cost at submaximal exercise was reduced after nitrate supplementation compared with placebo. On an average Vo(2) decreased from 2.98 +/- 0.57 during CON to 2.82 +/- 0.58 L min(-1) during NIT (P < 0.02) over the four lowest submaximal work rates. Gross efficiency increased from 19.7 +/- 1.6 during CON to 21.1 +/- 1.3% during NIT (P < 0.01) over the four lowest work rates. There was no difference in heart rate, lactate [Hla], ventilation (VE), VE/Vo(2) or respiratory exchange ratio between nitrate and placebo during any of the submaximal work rates. CONCLUSION: We conclude that dietary nitrate supplementation, in an amount achievable through a diet rich in vegetables, results in a lower oxygen demand during submaximal work. This highly surprising effect occurred without an accompanying increase in lactate concentration, indicating that the energy production had become more efficient. The mechanism of action needs to be clarified but a likely first step is the in vivo reduction of dietary nitrate into bioactive nitrogen oxides including nitrite and NO.

  • 174.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    The low intracellular oxygen tension during exercise is a function of limited oxygen supply and high mitochondrial oxygen affinity: A letter to the editor2012In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, no 11, p. 3935-3936Article in journal (Other academic)
    Abstract [en]

    A letter to the editor is presented in response to an article on muscle intracellular oxygenation during exercise published in a previous issue of the journal.

  • 175.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Mitochondrial oxygen affinity predicts basal metabolic rate in humans2011In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 25, no 8, p. 2843-52Article in journal (Refereed)
    Abstract [en]

    The basal metabolic rate (BMR) is referred to as the minimal rate of metabolism required to support basic body functions. It is well known that individual BMR varies greatly, even when correcting for body weight, fat content, and thyroid hormone levels, but the mechanistic determinants of this phenomenon remain unknown. Here, we show in humans that mass-related BMR correlates strongly to the mitochondrial oxygen affinity (p50(mito); R(2)=0.66, P=0.0004) measured in isolated skeletal muscle mitochondria. A similar relationship was found for oxygen affinity and efficiency during constant-load submaximal exercise (R(2)=0.46, P=0.007). In contrast, BMR did not correlate to overall mitochondrial density or to proton leak. Mechanistically, part of the p50(mito) seems to be controlled by the excess of cytochrome c oxidase (COX) protein and activity relative to other mitochondrial proteins. This is illustrated by the 5-fold increase in p50(mito) after partial cyanide inhibition of COX at doses that do not affect maximal mitochondrial electron flux through the ETS. These data suggest that the interindividual variation in BMR in humans is primarily explained by differences in mitochondrial oxygen affinity. The implications of these findings are discussed in terms of a trade-off between aerobic efficiency and power.

  • 176.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Weitzberg, Eddie
    Lundberg, Jon
    Effects of dietary nitrate on blood pressure in healthy volunteers2006In: New England Journal of Medicine, ISSN 0028-4793, E-ISSN 1533-4406, Vol. 28, no 355(26), p. 2792-3Article in journal (Refereed)
    Abstract [en]

    To the Editor:

    Nitric oxide, generated by nitric oxide synthase, is a key regulator of vascular integrity. This system is dysfunctional in many cardiovascular disorders, including hypertension. A fundamentally different pathway for the generation of nitric oxide was recently described in which the anions nitrate (NO3 ) and nitrite (NO2 ) are converted into nitric oxide and other bioactive nitrogen oxides.1-3 Nitrate is abundant in our diet, and particularly high levels are found in many vegetables.3

    We examined the effect of 3-day dietary supplementation with either sodium nitrate (at a dose of 0.1 mmol per kilogram of body weight per day) or placebo (sodium chloride, at a dose of 0.1 mmol per kilogram per day) on blood pressure in 17 physically active, healthy volunteers, none of whom smoked (15 men and 2 women; mean age, 24 years). The study had a randomized, double-blind, crossover design with two different treatment periods during which the subjects received either nitrate or placebo; the treatment periods were separated by a washout period of at least 10 days. The compounds were dissolved in water and could not be distinguished by taste or appearance. During the two treatment periods, the subjects were instructed to avoid all foods with a moderate or high nitrate content.3

    Systolic blood pressure Effects of 3-Day Dietary Supplementation with Inorganic Nitrate or Placebo on Systolic (Panel A) and Diastolic (Panel B) Blood Pressure in 17 Healthy Volunteers.) and pulse rate did not change significantly after nitrate supplementation, as compared with placebo supplementation. However, the diastolic blood pressure was on average 3.7 mm Hg lower after nitrate supplementation than after placebo supplementation (P<0.02) (Figure 1B), and the mean arterial pressure was 3.2 mm Hg lower (P<0.03). Plasma nitrate levels were higher after nitrate ingestion than after placebo ingestion (mean [±SD], 178±51 and 26±11 μM, respectively; P<0.001), as were plasma nitrite levels (219±105 and 138±38 nM, respectively; P<0.01).

    The daily nitrate dose used in the study corresponds to the amount normally found in 150 to 250 g of a nitrate-rich vegetable such as spinach, beetroot, or lettuce. It is clear from earlier studies, such as the Dietary Approaches to Stop Hypertension (DASH) trial, that a diet rich in fruits and vegetables can reduce blood pressure,4,5 but attempts to modify single nutrients have been inconsistent. Therefore, it has been argued that the effect of any individual nutrient is too small to detect in trials. In our study, reduced blood pressure was associated with nitrate supplementation alone; this effect was evident in young normotensive subjects. In fact, it was similar to that seen in the healthy control group in the DASH study.4 The exact mechanism behind the blood-pressure–lowering effect of nitrate needs to be clarified in future studies.

    We conclude that short-term dietary supplementation with inorganic nitrate reduces diastolic blood pressure in healthy young volunteers.

  • 177.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Anderson, Martin
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Nyström, Thomas
    Cardiorespiratory fitness predicts insulin action and secretion in healthy individuals.2012In: Metabolism: Clinical and Experimental, ISSN 0026-0495, E-ISSN 1532-8600, Vol. 61, no 1, p. 12-6Article in journal (Refereed)
    Abstract [en]

    Long-term cardiorespiratory fitness (CRF) and the development of type 2 diabetes mellitus are inversely correlated. Here, we examined the relationships between peak oxygen uptake (VO(2)peak), on the one hand, and glucose infusion rate at rest (GIR(rest)) and during exercise (GIR(exercise)), as well as insulin secretion (both the early and late phases of response [area under the curve {AUC}(insulin)]), on the other. Eight male and 4 female healthy, lean, nonsmoking volunteers were recruited. The VO(2)peak was measured during graded exercise on a cycle ergometer until exhaustion was reached. The GIR(rest) and GIR(exercise) were determined using a euglycemic-hyperinsulinemic clamp, and insulin secretion at rest was evaluated with an intravenous glucose tolerance test. The VO(2)peak correlated positively to GIR(rest) (r = 0.81, P = .001) and GIR(exercise) (r = 0.87, P < .001) and negatively to AUC(insulin) (r = -0.64, P = .03). The respiratory exchange ratio (RER) during insulin infusion was positively correlated to GIR(rest) (r = 0.83, P < .001) and GIR(exercise) (r = 0.86, P < .01) and negatively correlated to both the early insulin response (r = -0.86, P < .0001) and AUC(insulin) (r = -0.87, P = .001). The VO(2)peak accounted for 45% of the variability in RER (R(2) = 0.45, P = .035). In this healthy population, CRF and RER were highly correlated to insulin sensitivity and secretion, as well as to the ability to alter the substrate being oxidized during exercise. These findings highlight the importance of good CRF to maintaining normal insulin action.

  • 178.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Schiffer, Tomas A
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Mattsson, Mathias P
    Checa, Antonio
    Wheelock, Craig E
    Nyström, Thomas
    Lundberg, Jon O
    Weitzberg, Eddie
    Dietary nitrate reduces resting metabolic rate: a randomized, crossover study in humans.2014In: American Journal of Clinical Nutrition, ISSN 0002-9165, E-ISSN 1938-3207, Vol. 99, no 4, p. 843-50Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Nitrate, which is an inorganic anion abundant in vegetables, increases the efficiency of isolated human mitochondria. Such an effect might be reflected in changes in the resting metabolic rate (RMR) and formation of reactive oxygen species. The bioactivation of nitrate involves its active accumulation in saliva followed by a sequential reduction to nitrite, nitric oxide, and other reactive nitrogen species.

    OBJECTIVE: We studied effects of inorganic nitrate, in amounts that represented a diet rich in vegetables, on the RMR in healthy volunteers.

    DESIGN: In a randomized, double-blind, crossover study, we measured the RMR by using indirect calorimetry in 13 healthy volunteers after a 3-d dietary intervention with sodium nitrate (NaNO3) or a placebo (NaCl). The nitrate dose (0.1 mmol · kg(-1) · d(-1)) corresponded to the amount in 200-300 g spinach, beetroot, lettuce, or other vegetable that was rich in nitrate. Effects of direct nitrite exposure on cell respiration were studied in cultured human primary myotubes.

    RESULTS: The RMR was 4.2% lower after nitrate compared with placebo administration, and the change correlated strongly to the degree of nitrate accumulation in saliva (r(2) = 0.71). The thyroid hormone status, insulin sensitivity, glucose uptake, plasma concentration of isoprostanes, and total antioxidant capacity were unaffected by nitrate. The administration of nitrite to human primary myotubes acutely inhibited respiration.

    CONCLUSIONS: Dietary inorganic nitrate reduces the RMR. This effect may have implications for the regulation of metabolic function in health and disease.

  • 179.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Weitzberg, Eddie
    Lundberg, Jon O
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Dietary nitrate reduces maximal oxygen consumption while maintaining work performance in maximal exercise.2010In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 48, no 2, p. 342-7Article in journal (Refereed)
    Abstract [en]

    The anion nitrate-abundant in our diet-has recently emerged as a major pool of nitric oxide (NO) synthase-independent NO production. Nitrate is reduced stepwise in vivo to nitrite and then NO and possibly other bioactive nitrogen oxides. This reductive pathway is enhanced during low oxygen tension and acidosis. A recent study shows a reduction in oxygen consumption during submaximal exercise attributable to dietary nitrate. We went on to study the effects of dietary nitrate on various physiological and biochemical parameters during maximal exercise. Nine healthy, nonsmoking volunteers (age 30+/-2.3 years, VO(2max) 3.72+/-0.33 L/min) participated in this study, which had a randomized, double-blind crossover design. Subjects received dietary supplementation with sodium nitrate (0.1 mmol/kg/day) or placebo (NaCl) for 2 days before the test. This dose corresponds to the amount found in 100-300 g of a nitrate-rich vegetable such as spinach or beetroot. The maximal exercise tests consisted of an incremental exercise to exhaustion with combined arm and leg cranking on two separate ergometers. Dietary nitrate reduced VO(2max) from 3.72+/-0.33 to 3.62+/-0.31 L/min, P<0.05. Despite the reduction in VO(2max) the time to exhaustion trended to an increase after nitrate supplementation (524+/-31 vs 563+/-30 s, P=0.13). There was a correlation between the change in time to exhaustion and the change in VO(2max) (R(2)=0.47, P=0.04). A moderate dietary dose of nitrate significantly reduces VO(2max) during maximal exercise using a large active muscle mass. This reduction occurred with a trend toward increased time to exhaustion implying that two separate mechanisms are involved: one that reduces VO(2max) and another that improves the energetic function of the working muscles.

  • 180.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Schiffer, TA
    Borniquel, S
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Lundberg, JO
    Weitzberg, E
    Dietary inorganic nitrate improves mitochondrial efficiency in humans.2011In: Cell Metabolism, ISSN 1550-4131, Vol. 13, no 2, p. 149-159Article in journal (Refereed)
    Abstract [en]

    Nitrate, an inorganic anion abundant in vegetables, is converted in vivo to bioactive nitrogen oxides including NO. We recently demonstrated that dietary nitrate reduces oxygen cost during physical exercise, but the mechanism remains unknown. In a double-blind crossover trial we studied the effects of a dietary intervention with inorganic nitrate on basal mitochondrial function and whole-body oxygen consumption in healthy volunteers. Skeletal muscle mitochondria harvested after nitrate supplementation displayed an improvement in oxidative phosphorylation efficiency (P/O ratio) and a decrease in state 4 respiration with and without atractyloside and respiration without adenylates. The improved mitochondrial P/O ratio correlated to the reduction in oxygen cost during exercise. Mechanistically, nitrate reduced the expression of ATP/ADP translocase, a protein involved in proton conductance. We conclude that dietary nitrate has profound effects on basal mitochondrial function. These findings may have implications for exercise physiology- and lifestyle-related disorders that involve dysfunctional mitochondria.

  • 181. Leijon, M.
    et al.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Faskunger, J.
    Lärum, G.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Ståhle, A.
    Thúc đẩy hoạt động thể lực Chương 4. [Promoting physical activity. Chapter 4].2012In: HOạT ĐộNG THể LựC TRONG PHÒNG VÀ ĐIềU TRị BệNH. [Professional associations for physical activity YFA. Physical Activity in the Prevention and Treatment of Disease (In Vietnamese)]., Nhà xuất bản Y học Hà Nội, năm , 2012, p. 93-114Chapter in book (Other academic)
  • 182.
    Lidin, Matthias
    et al.
    Karolinska institutet.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Rydell Karlsson, Monica
    Karolinska institutet.
    Hellénius, Mai-Lis
    Karolinska institutet.
    Long-term effects of a Swedish lifestyle intervention programme on lifestyle habits and quality of life in people with increased cardiovascular risk.2017In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, article id 1403494817746536Article in journal (Refereed)
    Abstract [en]

    AIMS: The aim of this study was to evaluate the effects of a structured intervention programme on lifestyle habits and quality of life after six months and one year in participants with increased cardiovascular risk.

    METHODS: Participants aged ≥18 years with increased cardiovascular risk were referred from primary health care and hospitals. The programme was launched at an outpatient clinic in a department of cardiology at a university hospital. It consisted of individual visits to a nurse for a health check-up and lifestyle counselling at baseline, after six months and at one year. In addition, five group sessions - focusing on nicotine, alcohol, physical activity, eating habits, stress, sleep and behavioural change - were offered to the participants and their relatives or friends. Lifestyle habits and quality of life were assessed with questionnaires at baseline, after six months and at one year.

    RESULTS: One hundred participants (64 women, 36 men, age 58±11 years) were included in the programme. Compared with the baseline, significant and favourable changes in reported lifestyle habits were noted. Exercise levels were higher after one year and sedentary time decreased from 7.4 to 6.3 h/day. Dietary habits improved and the number of participants with a high consumption of alcohol decreased. Quality of life improved after one year.

    CONCLUSIONS: Participating in a structured lifestyle programme resulted in improved lifestyle habits and quality of life over one year in people with increased cardiovascular risk. Components such as an inter-professional teamwork, a focus on lifestyle rather than the disease, and combining individual visits and group sessions, might be central to the positive outcome of the programme.

  • 183. Lindegård, Agneta
    et al.
    Jonsdottir, Ingibjörg H
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Lindwall, Magnus
    Gerber, Markus
    Changes in mental health in compliers and non-compliers with physical activity recommendations in patients with stress-related exhaustion.2015In: BMC Psychiatry, ISSN 1471-244X, E-ISSN 1471-244X, Vol. 15, article id 272Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: There is a lack of research regarding the long-lasting effects of a more physically active lifestyle in patients with mental disorders. In the present study, clinical data were analysed to examine if initially physically inactive patients, clinically diagnosed with stress-related exhaustion, taking part in 12-month multimodal treatment (MMT), differ at the 18-month follow-up regarding mental health, depending on whether they did or did not comply with the physical activity (PA) recommendations resembling those of the American College of Sports Medicine.

    METHODS: The study population consisted of 69 patients (65 % women) who were referred to a stress clinic due to stress-related exhaustion. All patients received MMT. A major goal was to increase patients' PA levels. The patients received general comprehensive instructions including personal advice regarding the positive effects of PA on mental health and could self-select for an 18-week coached exercise program. Changes in mental health symptoms over an 18-month period were compared between non-compliers (n = 26), mild compliers (n = 22) and strong compliers (n = 21) with the PA recommendations included in the MMT.

    RESULTS: Non-compliers, mild and strong compliers did not differ regarding burnout, depression and anxiety at baseline. Although substantial improvements occurred in all groups, mild and strong compliers reported significantly lower burnout and depression levels at the 18-month follow-up than the non-complying group (p < .05). The general pattern of findings was corroborated, if standard cut-off criteria for clinical burnout were used.

    CONCLUSIONS: Compliance with PA recommendations is associated with decreased levels of burnout and depression in patients with stress-related exhaustion. Thus, the promotion of a more active lifestyle among patients with stress-related exhaustion should be implemented as a part of MMT, to achieve a more sustainable decrease of symptoms of burnout and depression.

    TRIAL REGISTRATION: This is not a clinical trial.

  • 184.
    Lindgren, Martin
    et al.
    Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra.
    Börjesson, Mats
    Department of Food, Nutrition and Sports Science, Institute of Neuroscience and Physiology, Sahlgrenska Academy and, Sahlgrenska University Hospital/Östra.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Bergström, Göran
    Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra.
    Lappas, Georgios
    Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra.
    Rosengren, Annika
    Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra.
    Physical activity pattern, cardiorespiratory fitness, and socioeconomic status in the SCAPIS pilot trial — A cross-sectional study2016In: Preventive Medicine Reports, ISSN 0350-1159, E-ISSN 2211-3355, Vol. 4, p. 44-49Article in journal (Refereed)
    Abstract [en]

    Living in a low socioeconomic status (SES) area is associated with an increased risk of cardiovascular events and all-cause mortality. Previous studies have suggested a socioeconomic gradient in daily physical activity (PA), but have mainly relied on self-reported data, and individual rather than residential area SES. This study aimed to investigate the relationships between residential area SES, PA pattern, compliance with PA-recommendations and fitness in a Swedish middle-aged population, using objective measurements. We included 948 individuals from the SCAPIS pilot study (Gothenburg, Sweden, 2012, stratified for SES, 49% women, median age: 58years), in three low and three high SES districts. Accelerometer data were summarized into intensity-specific categories: sedentary (SED), low (LIPA), and medium-to-vigorous PA (MVPA). Fitness was estimated by submaximal ergometer testing. Participants of low SES areas had a more adverse cardiovascular disease risk factor profile (smoking: 20% vs. 6%; diabetes: 9% vs. 3%; hypertension: 38% vs. 25%; obesity: 31% vs. 13%), and less frequently reached 150min of MVPA per week (67% vs. 77%, odds ratio [OR]=0.61; 95% confidence interval [95% CI]=0.46–0.82), from 10-minute bouts (19% vs. 31%, OR=0.53, 95% CI=0.39–0.72). Individuals in low SES areas showed lower PA levels (mean cpm: 320 vs. 348) and daily average MVPA (29.9 vs. 35.5min), and 12% lower fitness (25.1 vs. 28.5mL×min−1×kg−1) than did those in high SES areas. Reduced PA and fitness levels may contribute to social inequalities in health, and should be a target for improved public health in low SES areas.

  • 185. Lindwall, Magnus
    et al.
    Gerber, Markus
    Jonsdottir, Ingibjörg H
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Ahlborg, Gunnar
    The relationships of change in physical activity with change in depression, anxiety, and burnout: A longitudinal study of Swedish healthcare workers.2014In: Health Psychology, ISSN 0278-6133, E-ISSN 1930-7810, Vol. 33, no 11, p. 1309-1318Article in journal (Refereed)
    Abstract [en]

    Objective: The purpose of the present study was to examine whether intraindividual changes in physical activity were correlated with intraindividual changes in mental health (depression, anxiety, and burnout) across four measurement time-points over 6 years, both from between-person and within-person perspectives. Methods: Health care workers (N = 3717; mean age = 46.9; SD = 10.0) were the target population in this study, which is part of a larger longitudinal survey that included questionnaires on physical activity levels and mental health (depression, anxiety, and burnout) at four time points across 6 years (2004-2010). Physical activity was assessed with an adapted version of the widely used 1-item, 4-level Saltin Grimby Physical Activity Level Scale (SGPALS). Depression, anxiety, and burnout were assessed using the Hospital Anxiety and Depression (HAD) scale and the Shirom-Melamed Burnout Questionnaire (SMBQ). Bivariate latent growth curve models were used to analyze the associations of change between physical activity and mental health. Results: Baseline levels of physical activity were moderately associated with baseline levels of mental health (rs = -.27 to -.40, ps < .01). Changes in physical activity were moderately to strongly associated (rs = -.57 to -.79, ps <. 01) with change in mental health at the between-person (correlated change) level and significantly, but weakly (rs = -.08 to -.14, ps <.01), associated with change at the within-person (coupled change) level of analysis. Conclusions: Changes in physical activity were associated with, and traveled together with, changes in depression, anxiety, and burnout across time. Changes in physical activity, and not only current or previous levels of activity, may be important to consider in preventive work linked to mental health within this population. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  • 186. Löllgen, H.
    et al.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Cummiskey, J.
    Bachl, N.
    Debruyne, A.
    The Pre-Participation Examination in Sports: EFSMA Statement on ECG for Pre-Particpation Examination: Die sportärztliche Vorsorgeuntersuchung : Stellungnahme der EFSMA zur Bedeutung des EKG in der Vorsorgeuntersuchung2015In: Deutsche Zeitschrift für Sportmedizin, ISSN 0344-5925, Vol. 66, no 6, p. 151-155Article in journal (Refereed)
    Abstract [en]

    Goals of pre-participation examination (PPE) in athletes are primarily to protect health of athletes. This applies for children, adolescents, leisure time and top athletes. To recognise early possible risks, history and clinical examination is agreed to be the basis of PPE. However, there is a long-standing  controversy about whether ECG at rest should also be mandatory for all athletes. ECG is rejected in the US but included in most European countries.

    In addition, some large sports organisations also require ECG in PPE of athletes. The resting ECG can detect potential life-threatening diseases such as cardiomyopathies or ion-channel diseases ,thus avoiding sudden cardiac events or even death. The present paper discusses many arguments pro and contra ECG in athlete's screening. Arguments against are organisational problems, as sports physicians are not present nationwide in the US. Main arguments against are the lack of large prospective studies demonstrating reduced mortality by ECG, and the low sensitivity, specificity and predictive values of the ECG.

    However, current studies, new stringent and reliable criteria for ECG interpretation (e.g. Seattle criteria) increased the validity: false positive and negative findings decrease significantly. This is also supported by new, athlete-related ECG interpretation software in ECG devices, which are more reliable than visual analysis. This also may reduce legal problems, whereas psychological problems are of low importance as has been shown recently. Therefore, ECG recording in all athletes is strongly recommended in Europe. ECG is superior to history and clinical exam in detecting hidden and congenital diseases.

    However, special education in sports cardiology is advised, courses and training in ECG interpretation in athletes, as well as special ECG devices are mandatory for correct ECG interpretation in athletes.

  • 187. Malm, Christer
    et al.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Immune system alteration in response to increased physical training during a five day soccer training camp.2004In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 25, no 6, p. 471-6Article in journal (Refereed)
    Abstract [en]

    Leukocyte and monocyte subpopulations were investigated in ten elite male soccer players before and after a 5-day training camp. It was hypothesized that with increased training intensity and duration, the immune system would show signs of depression. Blood samples were taken at rest before and after the training camp and cell surface antigens were investigated by four-colour flow cytometry. After five days of intensified training, there was a significant decrease in the number of T helper, T cytotoxic and B cells, the expression of CD11 b on leukocytes increased and the NK cell population did not change significantly. It is concluded that after a period of intensified training, soccer players may experience decreased T and B cell numbers in circulation, possibly affecting their capability to activate the immune system and resist infections. However, in contrast to the acute decrease in the number of circulating NK cells commonly observed after physical exercise, no change in this cell population was observed at rest after a period of intensified physical training. Exercise-induced immunological changes were highly differentiated between different leukocyte subpopulations.

  • 188. Malm, Christer
    et al.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Immune system alteration in response to two consecutive soccer games.2004In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 180, no 2, p. 143-55Article in journal (Refereed)
    Abstract [en]

    AIM: Changes in leucocyte and monocyte subpopulations were investigated in 10 elite male soccer players aged 16-19 years. The purpose was to perform a descriptive study of immunological alterations in elite soccer players in response to two consecutive games separated by 20 h. It was hypothesized that in response to two games the players would show signs of short-term immunosuppression. METHODS: Blood samples were taken before the first soccer game, immediately after the second game and after 6, 24, 48 and 72 h. Cell surface antigens, testosterone and cortisol were investigated. RESULTS: During the first 6 h after the second game there was a significant increase in number of circulating neutrophils, mature (CD20+ CD5+) B cells and CD4/CD8 ratio. A significant decrease was observed in the number of natural killer (NK) cells, monocytes and adhesion on lymphocytes and monocytes. In a delayed phase, 48 h after the second game the expression of both adhesion and signalling molecules increased on lymphocytes and monocytes. Changes in adhesion and signalling molecules at 48 h correlated negatively to the subjects VO2max, suggesting larger immunological response to similar exercise in subjects with lower aerobic exercise capacity. CONCLUSION: In response to competitive soccer exercise some immunological variables are enhanced while others are depressed. Observed changes may serve a purpose in adaptation to exercise by signalling via adhesion.

  • 189. Malm, Christer
    et al.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Immunological Alterations Used to Predict Infections in Response to Strenuous Physical Training2011In: Military medicine, ISSN 0026-4075, E-ISSN 1930-613X, Vol. 176, no 7, p. 785-790Article in journal (Refereed)
    Abstract [en]

    ABSTRACT The aim of this study was to screen leukocyte cell surface markers to identify possible predictors for infection related to physical training. Ten healthy soldiers (mean age, 19.1; mean body mass, 77.4 kg; mean VO ^sub 2^ peak, 4.54 L min ^sup -1^ /58.6 mL min ^sup -1^ kg ^sup -1^ ) were included. Blood samples were collected and number of infections recorded before and after a 6-day training course. White blood cell distributions and expression of surface receptors changed during training. Before training, expression of CD3 on CD8  lymphocytes and percent CD8 CD3 lymphocytes was lower, whereas CD4/CD8 ratio was higher among subjects who failed compared to those who completed the training. A subclinical infection before the start of the military training may alter the CD4/CD8 ratio. Prediction of future infections may be possible from pre-exercise immunological status, fi ndings useful in military settings and exercise, where sudden infections may result in severe consequences.  

  • 190. Malm, Christer
    et al.
    Sjödin, The Late Bertil
    Sjöberg, Berit
    Lenkei, Rodica
    Renström, Per
    Lundberg, Ingrid E
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Leukocytes, cytokines, growth factors and hormones in human skeletal muscle and blood after uphill or downhill running.2004In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 556, no Pt 3, p. 983-1000Article in journal (Refereed)
    Abstract [en]

    Muscular adaptation to physical exercise has previously been described as a repair process following tissue damage. Recently, evidence has been published to question this hypothesis. The purpose of this study was to investigate inflammatory processes in human skeletal muscle and epimysium after acute physical exercise with large eccentric components. Three groups of subjects (n= 19) performed 45 min treadmill running at either 4 deg (n= 5) or 8 deg (n= 9) downhill or 4 deg uphill (n= 5) and one group served as control (n= 9). One biopsy was taken from each subject 48 h post exercise. Blood samples were taken up to 7 days post exercise. Compared to the control group, none of the markers of inflammation in muscle and epimysium samples was different in any exercised group. Only subjects in the Downhill groups experienced delayed onset of muscle soreness (DOMS) and increased serum creatine kinase activity (CK). The detected levels of immunohistochemical markers for T cells (CD3), granulocytes (CD11b), leukaemia inhibitory factor (LIF) and hypoxia-inducible factor 1beta (HIF-1beta) were greater in epimysium from exercised subjects with DOMS ratings >3 (0-10 scale) compared to exercised subjects without DOMS but not higher than controls. Eccentric physical exercise (downhill running) did not result in skeletal muscle inflammation 48 h post exercise, despite DOMS and increased CK. It is suggested that exercise can induce DOMS by activating inflammatory factors present in the epimysium before exercise. Repeated physical training may alter the content of inflammatory factors in the epimysium and thus reduce DOMS.

  • 191. Mandroukas, A
    et al.
    Heller, J
    Metaxas, T I
    Christoulas, K
    Vamvakoudis, E
    Stefanidis, P
    Papavasileiou, A
    Kotoglou, K
    Balasas, D
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mandroukas, K
    Deltoid muscle characteristics in wrestlers.2010In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 31, no 3, p. 148-53Article in journal (Refereed)
    Abstract [en]

    The purpose of the present study was to investigate the deltoid muscle characteristics of wrestlers. Nine Greco-Roman competitive male wrestlers (mean age 20.1+/-2.7 yrs, height 175+/-0.6 cm, weight 83.2+/-12.5 kg, years of training 7.6+/-2.7 yrs) participated in this study. Six male healthy sedentary students (mean age 21.2+/-0.9 yrs, height 180+/-0.3 cm, weight 80.1+/-9.4 kg) served as controls. Muscle fibre distribution, cross-sectional area (CSA), as well as satellite cells, myonuclei and capillary density per muscle fibre area were determined by immunohistochemistry. Myosin heavy chain MHC isoform composition of single fibres was determined with protein electrophoresis. Immunohistochemical analysis showed that muscle fibre distribution of the MHC I and IIA were significantly higher in wrestlers than in controls (p<0.05). Electrophoretic analysis of single fibres revealed a significantly higher proportion of fibres containing MHC I and IIC in wrestlers (p<0.05). The mean CSA of type IIA fibres and the number of myonuclei per type II was significantly higher in wrestlers (p<0.05). We also found that the number of satellite cells was 2.5 fold higher in wrestlers than in the control group. This study suggests that the observed muscle fibre profile in the deltoid of wrestlers may represent an adaptation based on the specific mechanical and biochemical demands of the long-term training in Greco-Roman wrestling.

  • 192. Mandroukas, A
    et al.
    Metaxas, T
    Kesidis, N
    Christoulas, K
    Vamvakoudis, E
    Stefanidis, P
    Heller, J
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mandroukas, K
    Deltoid muscle fiber characteristics in adolescent and adult wrestlers.2010In: Journal of Sports Medicine and Physical Fitness, ISSN 0022-4707, E-ISSN 1827-1928, Vol. 50, no 2, p. 113-20Article in journal (Refereed)
    Abstract [en]

    Our findings suggest that the observed muscle fiber profile in the deltoid muscle of wrestlers may represent an adaptation based on the mechanical and biochemical demands of the long-term training. Such adaptations are linked to the specific characteristics of the training program, the level and the previous training experience of the wrestlers.

  • 193.
    Marcus, Moberg
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Apró, William
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    van Hall, Gerrit
    Holmberg, Hans-Christer
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Lower body endurance exercise acutely affects resistance exercise induced transcriptional and translational signalling in the tricpes brachii muscleManuscript (preprint) (Other academic)
  • 194. Marklund, Peter
    et al.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Wåhlin-Larsson, Britta
    Ponsot, Elodie
    Lindvall, Björn
    Lindvall, Lisbeth
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Kadi, Fawzi
    Extensive inflammatory cell infiltration in human skeletal muscle in response to an ultra-endurance exercise bout in experienced athletes.2013In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 114, no 1, p. 66-72Article in journal (Refereed)
    Abstract [en]

    The impact of a 24h ultra-endurance exercise bout on systemic and local muscle inflammatory reactions was investigated in nine experienced athletes. Blood and muscle biopsies were collected before (PRE), immediately after the exercise (POST) and after 28h of recovery (POST28). Circulating blood levels of leukocytes, CK, CRP and selected inflammatory cytokines were assessed together with the evaluation of the occurrence of inflammatory cells (CD3(+), CD8(+), CD68(+)) and the expression of major histocompatibility complex class-I (MHC class-I) in skeletal muscle. An extensive inflammatory cell infiltration occurred in all athletes and the number of CD3(+), CD8(+) and CD 68(+) cells were 2-3 fold higher at POST28 compared to PRE (P<0.05). The inflammatory cell infiltration was associated with a significant increase in the expression of MHC class-I in muscle fibers. There was a significant increase in blood leukocyte count, IL-6, IL-8, CRP and CK at POST. At POST28 total leukocytes, IL-6 and CK had declined, whereas IL-8 and CRP continued to increase. Increases in IL-1β and TNF-α were not significant. There were no significant associations between the magnitude of the systemic and local muscle inflammatory reactions. Signs of muscle degenerative and regenerative events were observed in all athletes with various degrees of severity and were not affected by the ultra-endurance exercise bout. In conclusion, a low-intensity but very prolonged single endurance exercise bout can generate a strong inflammatory cell infiltration in skeletal muscle of well-trained experienced ultra-endurance athletes, and the amplitude of the local reaction is not proportional to the systemic inflammatory response.

  • 195.
    Mascher, Henrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Andersson, H
    Nilsson, P-A
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Changes in signalling pathways regulating protein synthesis in human muscle in the recovery period after endurance exercise.2007In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, no 1, p. 67-75Article in journal (Refereed)
    Abstract [en]

    AIM: Exercise induced alterations in the rate of muscle protein synthesis may be related to activity changes in signalling pathways involved in protein synthesis. The aim of the present study was to investigate whether such changes in enzyme phosphorylation occur after endurance exercise. METHODS: Six male subjects performed ergometer cycling exercise for 1 h at 75% of the maximal oxygen uptake. Muscle biopsy samples from the vastus lateralis were taken before, immediately after, 30 min, 1 h, 2 h and 3 h after exercise for the determination of protein kinase B (PKB/Akt), mammalian target of rapamycin (mTOR), glycogen synthase 3 kinase (GSK-3), p70S6 kinase (p70(S6k)) and eukaryotic elongation factor 2 (eEF2) phosphorylation. RESULTS: The phosphorylation of Akt was unchanged directly after exercise, but two- to fourfold increased 1 and 2 h after the exercise, whereas GSK-3alpha and beta phosphorylation were two- to fourfold elevated throughout most of the 3-h recovery period. Phosphorylation of mTOR was elevated threefold directly after, 30 min and 2 h after exercise and eEF2 phosphorylation was decreased by 35-75% from 30 min to 3 h-recovery. Exercise led to a five- to eightfold increase in Ser(424)/Thr(421) phosphorylation of p70(S6k) up to 30 min after exercise, but no change in Thr(389) phosphorylation. CONCLUSIONS: The marked decrease in eEF2 phosphorylation suggests an activation of translation elongation and possibly protein synthesis in the recovery period after sustained endurance exercise. The lack of p70(S6k) activation suggests that translation initiation is activated via alternative pathways, possibly via the activation of eukaryotic initiating factor 2B.

  • 196.
    Mascher, Henrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Rooyackers, Olav
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Enhanced rates of muscle protein synthesis and elevated mTOR signalling following endurance exercise in human subjects.2011In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 202, no 2, p. 175-84Article in journal (Refereed)
    Abstract [en]

    AIM: The major aim of this study was to determine the fractional rate of protein synthesis (FSR) during the early period of recovery after intensive aerobic exercise in the absence of nutritional supplementation.

    METHODS: Sixteen male subjects performed one-legged cycling exercise for 1 h at approx. 65-70% of their one-legged maximal oxygen uptake. Using the stable isotope technique, the FSR in the vastus lateralis of both legs were determined during two periods, 0-90 min (n = 8) and 90-180 min (n = 8) after exercise. Biopsies were taken from both exercising and resting muscle before exercise, immediately after and following 90 or 180 min of recovery.

    RESULTS: During the initial 90 min of recovery, FSR in the exercising muscle tended to be higher than in the resting muscle (1.57 ± 0.12 vs. 1.44 ± 0.07% 24 h(-1); P = 0.1) and was significantly higher during the period 90-180 min after exercise (1.74 ± 0.14 vs. 1.43 ± 0.12% 24 h(-1) ; P < 0.05). Exercise induced a 60% increase (P < 0.05) in phosphorylation of mTOR and a fivefold increase (P < 0.05) in Thr(389) phosphorylation of p70S6 kinase as well as a 30% reduction (P < 0.05) in phosphorylation of eEF2. Phosphorylation of AMP-activated protein kinase was enhanced by 40% (P < 0.05) after exercise, but no significant effect on phosphorylation of Akt, or eIF2Bε was observed immediately after exercise.

    CONCLUSION: These findings indicate that during the first 3 h of recovery after intensive endurance exercise FSR gradually increases. Moreover, a stimulation of the mTOR-signalling pathway may be at least partially responsible for this elevated protein synthesis.

  • 197.
    Mascher, Henrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Tannerstedt, Jörgen
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Brink-Elfegoun, Thibault
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Gustafsson, Thomas
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Repeated resistance exercise training induces different changes in mRNA expression of MAFbx and MuRF-1 in human skeletal muscle.2008In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 294, no 1, p. E43-51Article in journal (Refereed)
    Abstract [en]

    The gain in muscle mass as a result of resistance training is dependent on changes in both anabolic and catabolic reactions. A frequency of two to three exercise sessions per week is considered optimal for muscle gain in untrained individuals. Our hypothesis was that a second exercise session would enlarge the anabolic response and/or decrease the catabolic response. Eight male subjects performed resistance exercise on two occasions separated by 2 days. Muscle biopsies were taken from the vastus lateralis before and 15 min, 1 h, and 2 h after exercise. Exercise led to severalfold increases in phosphorylation of mTOR at Ser2448, p70 S6 kinase (p70S6k) at Ser424/Thr421 and Thr389, and ribosomal protein S6, which persisted for up to 2 h of recovery on both occasions. There was a tendency toward a larger effect of the second exercise on p70S6k and S6, but the difference did not reach statistical significance. The mRNA expression of MuRF-1, which increased after exercise, was 30% lower after the second exercise session than after the first one. MAFbx expression was not altered after exercise but downregulated 30% 48 h later, whereas myostatin expression was reduced by 45% after the first exercise and remained low until after the second exercise session. The results indicate that 1) changes in expression of genes involved in protein degradation are attenuated as a response to repetitive resistance training with minor additional increases in enzymes regulating protein synthesis and 2) the two ubiquitin ligases, MuRF-1 and MAFbx, are differently affected by the exercise as well as by repeated exercise.

  • 198.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Factors determining ultra-endurance exercise performance2014Conference paper (Refereed)
    Abstract [en]

    This talk will focus on the major nutritional and physiological factors that influence ultra-endurance exercise performance in both recreational and elite athletes.

    Empirical observations show that athletes who have been engaged in ultra-endurance sports for several years have a large advantage compared to novices in the sport. It depends of course in part on the fact that they are more experienced, but even athletes from traditional endurance sports with a documented higher aerobic capacity (i.e., higher VO2max) have difficulties to keep up with ultra-endurance specialists when exercise duration exceeds three or four hours. This indicates that fatigue and performance in ultra-endurance exercise is determined by (in part) other factors compared to traditional endurance sports.

    Ultra-endurance sports vary in form and duration, such as running or adventure racing (AR) from 6 h to more than 6 days, but are no matter the nature of the specific competition still in many aspects extreme sports.

    The athletes do not generally need to perform at high maximum speeds, but the energy expenditure is extremely high. The total energy expenditure for a 24-h AR is approximately 18-20 000 kcal, which is almost 10 times more than normal basal metabolism (Enqvist et al. 2010). One reason for fatigue is that the energy deficit is substantial, also the profile of amino acids in blood and muscle change during races (Borgenvik et al. 2012), possibly contributing to the central fatigue that has been described in other studies.

    As for the physiological factors, our research group and collaborators have investigated many aspects of the versatile physiological adaptation to ultra-endurance exercise, such as circulatory adaptations and cardiac fatigue (Mattsson 2011, Mattsson et al. 2010, 2011) muscular damage (Wichardt et al 2011, Marklund et al 2013), hormonal status (Berg et al 2008), and immunological response (Wallberg et al 2011).

    The effect of sleep deprivation on both mental and physiological functions during the races must also be included in the total complex of factors limiting performance.

  • 199.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Multisportens fysiologi2011In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 20, no 2, p. 50-53Article in journal (Other academic)
    Abstract [sv]

    Hur klarar kroppen flera dygn av tävling med relativt hög intensitet? Multisportare genomför sina lopp, men enligt traditionella fysiologiska förklaringsmodeller borde de ramla ihop av utmattning långt innan målgång. I vårt projekt ser vi hur kroppen och hjärtat istället anpassar sig till ansträngningarna utan några tecken på hjärtmuskelcellsskador.

  • 200.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Physiology of Adventure Racing: with emphasis on circulatory response and cardiac fatigue2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aims of this thesis were to elucidate the circulatory responses to ultra-endurance exercise (Adventure Racing), and furthermore, to contribute to the clarification of the so called “exercise-induced cardiac fatigue” in relation to said exercise. An Adventure race (AR) varies in duration from six hours to over six days, in which the participants have to navigate through a number of check-points over a pre-set course, using a combination of three or more endurance/outdoor sports, e.g., cycling, running, and kayaking. This thesis is based on the results from four different protocols; 12- and 24-h (n = 8 and 9, respectively) in a controlled setting with fixed exercise intensity, and 53-h and 5-7-day (n = 15 in each) in field setting under race conditions. The subjects in all protocols were experienced adventure racing athletes, competitive at elite level. Study I and II address the circulatory responses and cardiovascular drift, using methods for monitoring heart rate (HR), oxygen uptake (VO2), cardiac output (non-invasive re-breathing) and blood pressure, during ergometer cycling at fixed steady state work rate at periods before, during and after the ultra-endurance exercise. In Study III and IV we examined the possible presence of exercise-induced cardiac fatigue after a 5-7-day AR, from two different perspectives. In Study III analyses were performed with biochemical methods to determine circulating levels of cardiac specific biomarkers (i.e., creatine kinase isoenzyme MB (CK-MB), troponin I, B-type natriuretic peptide (BNP) and N-terminal prohormonal B-type natriuretic peptide (NT-proBNP)). We also made an attempt to relate increases in biomarkers to rated relative performance. In Study IV we used tissue velocity imaging (TVI) (VIVID I, GE VingMed Ultrasound, Norway) to determine whether the high workload (extreme duration) would induce signs of functional cardiac fatigue similar to those that occur in skeletal muscle, i.e., decreased peak systolic velocities. Using conventional echocardiography we also evaluated whether the hearts of experienced ultra-endurance athletes are larger than the normal upper limit. The central circulation changed in several steps in response to ultra-endurance exercise. Compared to initial levels, VO2 was increased at every time-point measured. The increase was attributed to peripheral adaptations, confirmed by a close correlation between change in VO2 and change in arteriovenous oxygen difference. The first step of the circulatory response was typical of normal (early) cardiovascular drift, with increased HR and concomitantly decreased stroke volume (SV) and oxygen pulse (VO2/HR), occurring over the first 4-6 h. The second step, which continued until approximately 12h, included reversed HR-drift, with normalisation of SV and VO2/HR. When exercise continued for 50 h a late cardiovascular drift was noted, characterised by increased VO2/HR, (indicating more efficient energy distribution), decreased peripheral resistance, increased SV, and decreased work of the heart. Since cardiac output was maintained at all-time points we interpret the changes as physiologically appropriate adaptations. Our findings in Study III point towards a distinction between the clinical/pathological and the physiological/exercise-induced release of cardiac biomarkers. The results imply that troponin and CKMB lack relevance in the (healthy) exercise setting, but that BNP, or NT-proBNP adjusted for exercise duration, might be a relevant indicator for impairment of exercise performance. High levels of NTproBNP, up to 2500 ng · l -1 , can be present after ultra-endurance exercise in healthy athletes without any subjective signs or clinical symptoms of heart failure. However, these high levels of NT-proBNP seemed to be associated with decreased relative exercise performance, and might be an indicator of the cardiac fatigue that has previously been described after endurance exercise. Study IV revealed that the sizes of the hearts (left ventricle) of all of our ultra-endurance athletes were within normal limits. The measurements of peak systolic velocities showed (for group average) no signs of cardiac fatigue even after 6 days of continuous exercise. This discrepancy between ours and other studies, involving e.g., marathon or triathlon, might reflect the fact that this type of exercise is performed at relatively low average intensity, suggesting that the intensity, rather than the duration, of exercise is the primary determinant of cardiac fatigue.

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