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Larsson, K., Kallings, L., Ekblom, Ö., Blom, V., Andersson, E. & Ekblom, M. (2019). Criterion validity and test-retest reliability of SED-GIH, a single item question for assessment of daily sitting time.. BMC Public Health, 19(1), Article ID 19:17.
Open this publication in new window or tab >>Criterion validity and test-retest reliability of SED-GIH, a single item question for assessment of daily sitting time.
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2019 (English)In: BMC Public Health, ISSN 1471-2458, E-ISSN 1471-2458, Vol. 19, no 1, article id 19:17Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Sedentary behaviour has been closely linked to metabolic and cardiovascular health and is therefore of importance in disease prevention. A user-friendly tool for assessment of sitting time is thus needed. Previous studies concluded that the present tools used to assess a number of sedentary behaviours are more likely to overestimate sitting than single-item questions which often underestimate sitting time, and that categorical answering options are recommended. In line with this, the single-item question with categorical answering options, SED-GIH, was developed. The aim of this study was to investigate the criterion validity of the SED-GIH question using activPAL3 micro as the criterion measure. The second aim was to evaluate the test-retest reliability of the SED-GIH questionnaire.

METHOD: In the validity section of this study, 284 middle-aged adults answered a web questionnaire, which included SED-GIH, wore activPAL and filled in a diary log for one week. Spearman's rho assessed the relationship between the SED-GIH answers and the daily average sitting time as monitored by the activPAL (activPAL-SIT), a Weighted Kappa assessed the agreement, ANOVA assessed differences in activPAL-SIT between the SED-GIH answer categories, and a Chi2 compared the proportions of hazardous sitters between the different SED-GIH answer categories. In the reliability section, 95 elderly participants answered the SED-GIH question twice, with a mean interval of 5.2 days. The reliability was assessed with ICC and a weighted Kappa.

RESULTS: The SED-GIH question correlated moderately with activPAL-SIT (rho = 0.31), with a poor agreement (weighted Kappa 0.12). In total, 40.8% underestimated and 22.2% overestimated their sitting time. The ANOVA showed significant differences in activPAL-SIT between the different SED-GIH answer categories (p < 0.001). The Chi2 showed a significant difference in proportion of individuals sitting more than 10 h per day within each SED-GIH answer category. ICC for the test-retest reliability of SED-GIH was excellent with ICC = 0.86, and the weighted Kappa showed an agreement of 0.77.

CONCLUSIONS: The unanchored single item SED-GIH question showed excellent reliability but poor validity in the investigated populations. Validity and reliability of SED-GIH is in line with other questionnaires that are commonly used when assessing sitting time.

Place, publisher, year, edition, pages
BioMed Central, 2019
Keywords
Adults, Office-based work, Older adults, Reliability, Sedentary behaviour, Sitting, Validity, activPAL
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5520 (URN)10.1186/s12889-018-6329-1 (DOI)30611226 (PubMedID)
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-01-08
Ekblom, M., Bojsen-Möller, E., Tarassova, O. & Ekblom, Ö. (2019). Day-to day variations in physical activity patterns affect corticospinal excitability on the following day. In: Brain Stimulation March-April 2019, vol 12, issue 2: . Paper presented at 3rd International Brain Stimulation Conference, Feb 24-27 2019, Vancouver (pp. 468). Elsevier, 12(2), Article ID 437.
Open this publication in new window or tab >>Day-to day variations in physical activity patterns affect corticospinal excitability on the following day
2019 (English)In: Brain Stimulation March-April 2019, vol 12, issue 2, Elsevier, 2019, Vol. 12, no 2, p. 468-, article id 437Conference paper, Oral presentation with published abstract (Other academic)
Place, publisher, year, edition, pages
Elsevier, 2019
National Category
Physiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5738 (URN)10.1016/j.brs.2018.12.523 (DOI)
Conference
3rd International Brain Stimulation Conference, Feb 24-27 2019, Vancouver
Available from: 2019-05-09 Created: 2019-05-09 Last updated: 2019-05-20Bibliographically approved
Hirschberg, A. L., Elings Knutsson, J., Helge, T., Godhe, M., Ekblom, M., Bermon, S. & Ekblom, B. (2019). Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study. British Journal of Sports Medicine
Open this publication in new window or tab >>Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study
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2019 (English)In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480Article in journal (Refereed) Epub ahead of print
Abstract [en]

Objective To investigate the effects of a moderate increase in serum testosterone on physical performance in young, physically active, healthy women.Methods A double blind, randomised, placebo controlled trial was conducted between May 2017 and June 2018 (ClinicalTrials.gov ID: NCT03210558). 48 healthy, physically active women aged 18–35 years were randomised to 10 weeks of treatment with 10 mg of testosterone cream daily or placebo (1:1). All participants completed the study. The primary outcome measure was aerobic performance measured by running time to exhaustion (TTE). Secondary outcomes were anaerobic performance (Wingate test) and muscle strength (squat jump (SJ), counter movement jump (CMJ) and knee extension peak torque). Hormone levels were analysed and body composition assessed by dual energy X-ray absorptiometry.Results Serum levels of testosterone increased from 0.9 (0.4) nmol/L to 4.3 (2.8) nmol/L in the testosterone supplemented group. TTE increased significantly by 21.17 s (8.5%) in the testosterone group compared with the placebo group (mean difference 15.5 s; P=0.045). Wingate average power, which increased by 15.2 W in the testosterone group compared with 3.2 W in the placebo group, was not significantly different between the groups (P=0.084). There were no significant changes in CMJ, SJ and knee extension. Mean change from baseline in total lean mass was 923 g for the testosterone group and 135 g for the placebo group (P=0.040). Mean change in lean mass in the lower limbs was 398 g and 91 g, respectively (P=0.041).Conclusion The study supports a causal effect of testosterone in the increase in aerobic running time as well as lean mass in young, physically active women.

Place, publisher, year, edition, pages
BMJ Publishing Group Ltd, 2019
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5869 (URN)10.1136/bjsports-2018-100525 (DOI)
Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2019-10-17Bibliographically approved
Gago, P., Arndt, A., Marques, M. C., Marinho, D. A. & Ekblom, M. (2019). Effects of post activation potentiation on electromechanical delay. Clinical Biomechanics, 70, 115-122
Open this publication in new window or tab >>Effects of post activation potentiation on electromechanical delay
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2019 (English)In: Clinical Biomechanics, ISSN 0268-0033, E-ISSN 1879-1271, Vol. 70, p. 115-122Article in journal (Refereed) Published
Abstract [en]

Electromechanical delay (EMD) presumably depends upon both contractile and tensile factors. It has recently been used as an indirect measure of muscle tendon stiffness to study adaptations to stretching and training. The aim of the present study was to investigate whether contractile properties induced by a 6 s maximum voluntary isometric contraction (MVIC) could affect EMD without altering passive muscle tendon stiffness or stiffness index. Plantar flexor twitches were evoked via electrical stimulation of the tibial nerve in eight highly trained male sprinters before and after a 6 s MVIC in passive isometric or passively shortening or lengthening muscles. For each twitch, EMD, twitch contractile properties and SOLM-Wave were measured. Passive muscle tendon stiffness was measured from the slope of the relation between torque and ankle angle during controlled passive dorsal flexion and stiffness index by curve-fitting the torque angle data using a second-order polynomial function. EMD did not differ between isometric, lengthening or shortening movements. EMD was reduced by up to 11.56 ± 5.64% immediately after the MVIC and stayed depressed for up to 60 s after conditioning. Peak twitch torque and rate of torque development were potentiated by up to 119.41 ± 37.15% and 116.06 ± 37.39%, respectively. Rising time was reduced by up to 14.46 ± 7.22%. No significant changes occurred in passive muscle tendon stiffness or stiffness index. Using a conditioning MVIC, it was shown that there was an acute enhancement of contractile muscle properties as well as a significant reduction in EMD with no corresponding changes in stiffness. Therefore, caution should be taken when using and interpreting EMD as a proxy for muscle tendon stiffness.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Muscle, Twitch, Potentiation, Electromechanical delay, Stiffness
National Category
Physiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5820 (URN)10.1016/j.clinbiomech.2019.08.001 (DOI)31476603 (PubMedID)
Note

At the time of Paulo Gago's dissertation this article was a manuscript.

Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-09-17Bibliographically approved
Psilander, N., Eftestøl, E., Cumming, K. T., Juvkam, I., Ekblom, M., Sunding, K., . . . Gundersen, K. (2019). Effects of training, detraining, and retraining on strength, hypertrophy, and myonuclear number in human skeletal muscle. Journal of applied physiology, 126(6), 1636-1645
Open this publication in new window or tab >>Effects of training, detraining, and retraining on strength, hypertrophy, and myonuclear number in human skeletal muscle
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2019 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 126, no 6, p. 1636-1645Article in journal (Refereed) Published
Abstract [en]

Previously trained mouse muscles acquire strength and volume faster than naïve muscles; it has been suggested that this is related to increased myonuclear density. The present study aimed to determine whether a previously strength-trained leg (mem-leg) would respond better to a period of strength training than a previously untrained leg (con-leg). Nine men and 10 women performed unilateral strength training (T1) for 10 weeks, followed by 20 weeks of detraining (DT) and a 5-week bilateral retraining period (T2). Muscle biopsies were taken before and after each training period and analyzed for myonuclear number, fiber volume, and cross-sectional area (CSA). Ultrasound and one repetition of maximum leg extension were performed to determine muscle thickness (MT) and strength. CSA (~17%), MT (~10%), and strength (~20%) increased during T1 in the mem-leg. However, the myonuclear number and fiber volume did not change. MT and CSA returned to baseline values during DT, but strength remained elevated (~60%), supporting previous findings of a long-lasting motor learning effect. MT and strength increased similarly in the mem-leg and con-leg during T2, whereas CSA, fiber volume, and myonuclear number remained unaffected. In conclusion, training response during T2 did not differ between the mem-leg and con-leg. However, this does not discount the existence of human muscle memory since no increase in the number of myonuclei was detected during T1 and no clear detraining effect was observed for cell size during DT; thus, the present data did not allow for a rigorous test of the muscle memory hypothesis.

Place, publisher, year, edition, pages
American Physiological Society, 2019
Keywords
CSA, exercise, motor learning, muscle memory, myonuclei
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5716 (URN)10.1152/japplphysiol.00917.2018 (DOI)000471217500014 ()30991013 (PubMedID)
Available from: 2019-04-23 Created: 2019-04-23 Last updated: 2019-08-14Bibliographically approved
Godhe, M., Ekblom, Ö., Ekblom, M., Pontén, M. & Andersson, E. (2019). Improved daily movement patterns in an accelerometer-assessed 8-weeks exercise project in older adults. In: British Journal of Sports Medicine Vol 53, suppl 1: . Paper presented at Scandinavian Sports Medicine Congress, Jan 30 - Feb 1 2019, Copenhagen (pp. A2). BMJ Publishing Group Ltd, 53
Open this publication in new window or tab >>Improved daily movement patterns in an accelerometer-assessed 8-weeks exercise project in older adults
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2019 (English)In: British Journal of Sports Medicine Vol 53, suppl 1, BMJ Publishing Group Ltd, 2019, Vol. 53, p. A2-Conference paper, Oral presentation with published abstract (Other academic)
Place, publisher, year, edition, pages
BMJ Publishing Group Ltd, 2019
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5737 (URN)10.1136/bjsports-2019-scandinavianabs.6 (DOI)
Conference
Scandinavian Sports Medicine Congress, Jan 30 - Feb 1 2019, Copenhagen
Available from: 2019-05-09 Created: 2019-05-09 Last updated: 2019-05-20Bibliographically approved
Nooijen, C. F., Blom, V., Ekblom, Ö., Ekblom, M. & Kallings, L. (2019). Improving office workers' mental health and cognition: a 3-arm cluster randomized controlled trial targeting physical activity and sedentary behavior in multi-component interventions. BMC Public Health, 19, Article ID 266.
Open this publication in new window or tab >>Improving office workers' mental health and cognition: a 3-arm cluster randomized controlled trial targeting physical activity and sedentary behavior in multi-component interventions
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2019 (English)In: BMC Public Health, ISSN 1471-2458, E-ISSN 1471-2458, Vol. 19, article id 266Article in journal (Refereed) Published
Abstract [en]

Background

Physically inactive and sedentary lifestyles are negatively related to both mental health and cognition. For office-workers, who spend two-thirds of their workday sitting, it is important to improve these lifestyles. The aim of this study is to assess the effectiveness of multi-component interventions, incorporating individual, environmental and organizational changes, to increase physical activity or reduce sedentary behavior among office-workers in order to improve mental health and cognition.

Methods

a 3-arm, clustered randomized controlled trial (RCT) with waiting list control group amongst adult office-workers of two large Swedish companies. Cluster teams will be randomized into 6-month interventions or to a passive waiting list control group which will receive the allocated intervention with a 6-month delay. Two multicomponent interventions will be studied of which one focuses on improving physical activity and the other on reducing sedentary behavior. Both interventions include 5 sessions of motivational counselling. In the physical activity intervention persons also get access to a gym and team leaders will organize lunch walks and encourage to exercise. In the sedentary behavior intervention standing- and walking meetings will be implemented and team leaders will encourage to reduce sitting. The recruitment target is 110 office-workers per arm (330 in total). Measurements will be repeated every 6months for a total intended duration of 24months. Proximal main outcomes are physical activity measured with accelerometers and sedentary behavior with inclinometers. Distal outcomes are self-reported mental health and a cognition test battery. Additional outcomes will include cardiovascular fitness, body composition, sleep, self-reported physical activity and sedentary behavior, other health habits, physical health, and working mechanisms from blood samples and questionnaires.

Discussion

This cluster RCT will contribute to the currently available evidence by comparing the effectiveness of multi-component interventions targeting physical activity or sedentary behavior with the end goal of improving mental health and cognition. This study is strong in its cluster randomized design, numerous objective outcome measures and long-term follow-up. The exact content of the interventions has been defined by combining theory with results from a larger research project as well as having a continuous dialogue with the involved companies.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5646 (URN)10.1186/s12889-019-6589-4 (DOI)000460405200003 ()30836957 (PubMedID)
Projects
Fysisk aktivitet och hälsosamma hjärnfunktioner bland kontorsarbetare: Delprojekt 3, Långsiktiga interventioner
Available from: 2019-03-19 Created: 2019-03-19 Last updated: 2019-08-06
Hendy, A. M., Ekblom, M., Latella, C. & Teo, W.-P. (2019). Investigating the effects of muscle contraction and conditioning stimulus intensity on short-interval intracortical inhibition.. European Journal of Neuroscience
Open this publication in new window or tab >>Investigating the effects of muscle contraction and conditioning stimulus intensity on short-interval intracortical inhibition.
2019 (English)In: European Journal of Neuroscience, ISSN 0953-816X, E-ISSN 1460-9568Article in journal (Refereed) Epub ahead of print
Abstract [en]

A reduction in short-interval intracortical inhibition (SICI) has been shown to accompany acute or chronic resistance exercise; however, little is known about how SICI is modulated under different contraction intensities. Therefore, the purpose of this study was to assess the effect of muscle contraction and conditioning stimulus intensity on the modulation of SICI. Single- and paired-pulse transcranial magnetic stimulation was applied to the primary motor cortex (M1), and motor evoked potentials (MEPs) were recorded from the biceps brachii in 16 adults (10M/6F). A conditioning-test stimulus paradigm (3 ms inter-stimulus intervals) was delivered during 10%, 20%, 40% and 75% of maximal voluntary isometric contraction (MVIC). At each force level, conditioning stimulus intensities of 60%, 70% and 80% of active motor threshold (AMT) were tested. Single-pulse MEPs were expressed as a proportion of the maximal muscle compound action potential, while SICI was quantified as a ratio of the unconditioned MEP. MEP amplitude increased with force output, with the greatest increase at 75% of MVIC. A reduction in SICI was observed from 40% to 75% of MVIC, but not 10%-40% of MVIC. There was no significant interaction between conditioning stimulus intensity and force level. The conditioning stimulus intensity (60%, 70% or 80% of AMT) did not alter the modulation of SICI. SICI was reduced at 75% of MVIC compared with the lower force outputs, and the magnitude of SICI in individual participants at different force outputs was not related. The findings suggest that strong muscle contractions are accompanied by less inhibition, which may have implications for neuroplasticity in exercise interventions.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
biceps brachii, motor evoked potential, muscle force, transcranial magnetic stimulation
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5803 (URN)10.1111/ejn.14488 (DOI)31199534 (PubMedID)
Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-14Bibliographically approved
Larsson, K., Ekblom, Ö., Kallings, L., Ekblom, M. & Blom, V. (2019). Job Demand-Control-Support Model as Related to Objectively Measured Physical Activity and Sedentary Time in Working Women and Men.. International Journal of Environmental Research and Public Health, 16(18), Article ID E3370.
Open this publication in new window or tab >>Job Demand-Control-Support Model as Related to Objectively Measured Physical Activity and Sedentary Time in Working Women and Men.
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2019 (English)In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 16, no 18, article id E3370Article in journal (Refereed) Published
Abstract [en]

A physically active lifestyle incurs health benefits and physically active individuals show reduced reactivity to psychosocial stressors. However, the findings are inconclusive and are based on self-reported physical activity and sedentary time. The present study aimed at studying the associations between psychological stressors (job demand, control, support, JD-C-S) and objectively measured physical activity (PA) on various intensities from sedentary (SED) to vigorous physical activity. The participants were 314 employees from a cross-sectional study. PA data were collected with the accelerometer ActiGraph GT3X (Pensacola, FL, USA), SED data with the inclinometer activPAL (PAL Technologies Ltd., Glasgow, Scotland, UK), and psychosocial stressors with a web questionnaire. Results showed that vigorous-intensity PA was negatively associated with demand (β -0.15, p < 0.05), even when adjusted for the covariates. SED was negatively associated to support (β -0.13, p < 0.05). Stress significantly moderated relations between support and sedentary time (β -0.12, p < 0.05). Moderate PA (MVPA) was negatively associated with demand, but only when controlling for overtime (β -0.13, p < 0.05). MVPA was also negatively associated with control (β -0.15, p < 0.05) but not when work engagement was included in the model. Being more physically active and spending less time sedentary may help to handle job situations with high demand and low support.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
ActiGraph, activPAL, job demand-control-support model, physical activity, questionnaire, sedentary time, workplace
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5858 (URN)10.3390/ijerph16183370 (DOI)31547253 (PubMedID)
Projects
Fysisk aktivitet och hälsosamma hjärnfunktioner bland kontorsarbetare: Delprojekt 1, Tvärsnittsstudie
Available from: 2019-09-26 Created: 2019-09-26 Last updated: 2019-09-30
Nooijen, C. F., Kallings, L., Blom, V., Ekblom, Ö., Forsell, Y. & Ekblom, M. (2018). Common Perceived Barriers and Facilitators for Reducing Sedentary Behaviour among Office Workers.. International Journal of Environmental Research and Public Health, 15(4), Article ID E792.
Open this publication in new window or tab >>Common Perceived Barriers and Facilitators for Reducing Sedentary Behaviour among Office Workers.
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2018 (English)In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 15, no 4, article id E792Article in journal (Refereed) Published
Abstract [en]

Qualitative studies identified barriers and facilitators associated with work-related sedentary behaviour. The objective of this study was to determine common perceived barriers and facilitators among office workers, assess subgroup differences, and describe sedentary behaviour. From two Swedish companies, 547 office workers (41 years (IQR = 35–48), 65% women, 66% highly educated) completed questionnaires on perceived barriers and facilitators, for which subgroup differences in age, gender, education, and workplace sedentary behaviour were assessed. Sedentary behaviour was measured using inclinometers (n = 311). The most frequently reported barrier was sitting is a habit (67%), which was reported more among women than men (X2 = 5.14, p = 0.03) and more among highly sedentary office workers (X2 = 9.26, p < 0.01). The two other most reported barriers were that standing is uncomfortable (29%) and standing is tiring (24%). Facilitators with the most support were the introduction of either standing- or walking-meetings (respectively 33% and 29%) and more possibilities or reminders for breaks (31%). The proportion spent sedentary was 64% at the workplace, 61% on working days, and 57% on non-working days. This study provides a detailed understanding of office workers’ ideas about sitting and means to reduce sitting. We advise to include the supported facilitators and individualized support in interventions to work towards more effective strategies to reduce sedentary behaviour.

Keywords
barriers, facilitators, office workers, sedentary behaviour, workplace
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5262 (URN)10.3390/ijerph15040792 (DOI)000434868800231 ()29670047 (PubMedID)
Projects
Fysisk aktivitet och hälsosamma hjärnfunktioner bland kontorsarbetare: Delprojekt 1, Tvärsnittsstudie
Available from: 2018-05-25 Created: 2018-05-25 Last updated: 2019-08-06
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7879-9188

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