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  • 1.
    Ainegren, Mats
    et al.
    Mid Sweden University.
    Jensen, Kurt
    University of Southern Denmark.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Breathing resistance in automated metabolic systems is high in comparison with the Douglas Bag method and previous recommendations2018In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, ISSN 1754-3371, Vol. 232, no 2, p. 122-130Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate the resistance to breathing in metabolic systems used for the distribution and measurement of pulmonary gas exchange. A mechanical lung simulator was used to standardize selected air flow rates (V·, L/s). The delta pressure (?p, Pa) between the ambient air and the air inside the equipment was measured in the breathing valve?s mouthpiece adapter for four metabolic systems and four types of breathing valves. Resistance for the inspiratory and expiratory sides was calculated as RES?=?(?p/V·)?Pa/L/s. The results for resistance showed significant (p?<?0.05) between-group variance among the tested metabolic systems, breathing valves, and between most of the completed V·. The lowest resistance among the metabolic systems was found for a Douglas Bag system which had approximately half of the resistance compared to the automated metabolic systems. The automated systems were found to have higher resistance even at low V· in comparison with previous findings and recommendations. For the hardware components, the highest resistance was found for the breathing valves, while the lowest resistance was found for the hoses. The results showed that resistance in metabolic systems can be minimized through conscious choices of system design and hardware components.

  • 2.
    Calbet, J A L
    et al.
    Department of Physical Education, University of Las Palmas de Gran Canaria, Spain.
    Holmberg, H-C
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    van Hall, Gerrit
    Jensen-Urstad, Mats
    Saltin, Bengt
    Why do arms extract less oxygen than legs during exercise?2005In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 289, no 5, p. R1448-58Article in journal (Refereed)
    Abstract [en]

    To determine whether conditions for O2 utilization and O2 off-loading from the hemoglobin are different in exercising arms and legs, six cross-country skiers participated in this study. Femoral and subclavian vein blood flow and gases were determined during skiing on a treadmill at approximately 76% maximal O2 uptake (V(O2)max) and at V(O2)max with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise), and leg skiing (predominantly leg exercise). The percentage of O2 extraction was always higher for the legs than for the arms. At maximal exercise (diagonal stride), the corresponding mean values were 93 and 85% (n = 3; P < 0.05). During exercise, mean arm O2 extraction correlated with the P(O2) value that causes hemoglobin to be 50% saturated (P50: r = 0.93, P < 0.05), but for a given value of P50, O2 extraction was always higher in the legs than in the arms. Mean capillary muscle O2 conductance of the arm during double poling was 14.5 (SD 2.6) ml.min(-1).mmHg(-1), and mean capillary P(O2) was 47.7 (SD 2.6) mmHg. Corresponding values for the legs during maximal exercise were 48.3 (SD 13.0) ml.min(-1).mmHg(-1) and 33.8 (SD 2.6) mmHg, respectively. Because conditions for O2 off-loading from the hemoglobin are similar in leg and arm muscles, the observed differences in maximal arm and leg O2 extraction should be attributed to other factors, such as a higher heterogeneity in blood flow distribution, shorter mean transit time, smaller diffusing area, and larger diffusing distance, in arms than in legs.

  • 3.
    Calbet, J A L
    et al.
    Department of Physical Education, University of Las Palmas de Gran Canaria, Spain.
    Jensen-Urstad, Mats
    van Hall, Gerrit
    Holmberg, H-C
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Saltin, Bengt
    Maximal muscular vascular conductances during whole body upright exercise in humans.2004In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 558, no Pt 1, p. 319-31Article in journal (Refereed)
    Abstract [en]

    That muscular blood flow may reach 2.5 l kg(-1) min(-1) in the quadriceps muscle has led to the suggestion that muscular vascular conductance must be restrained during whole body exercise to avoid hypotension. The main aim of this study was to determine the maximal arm and leg muscle vascular conductances (VC) during leg and arm exercise, to find out if the maximal muscular vasodilatory response is restrained during maximal combined arm and leg exercise. Six Swedish elite cross-country skiers, age (mean +/-s.e.m.) 24 +/- 2 years, height 180 +/- 2 cm, weight 74 +/- 2 kg, and maximal oxygen uptake (VO2,max) 5.1 +/- 0.1 l min(-1) participated in the study. Femoral and subclavian vein blood flows, intra-arterial blood pressure, cardiac output, as well as blood gases in the femoral and subclavian vein, right atrium and femoral artery were determined during skiing (roller skis) at approximately 76% of VO2max and at VO2max with different techniques: diagonal stride (combined arm and leg exercise), double poling (predominantly arm exercise) and leg skiing (predominantly leg exercise). During submaximal exercise cardiac output (26-27 l min(-1)), mean blood pressure (MAP) (approximately 87 mmHg), systemic VC, systemic oxygen delivery and pulmonary VO2(approximately 4 l min(-1)) attained similar values regardless of exercise mode. The distribution of cardiac output was modified depending on the musculature engaged in the exercise. There was a close relationship between VC and VO2 in arms (r= 0.99, P < 0.001) and legs (r= 0.98, P < 0.05). Peak arm VC (63.7 +/- 5.6 ml min(-1) mmHg(-1)) was attained during double poling, while peak leg VC was reached at maximal exercise with the diagonal technique (109.8 +/- 11.5 ml min(-1) mmHg(-1)) when arm VC was 38.8 +/- 5.7 ml min(-1) mmHg(-1). If during maximal exercise arms and legs had been vasodilated to the observed maximal levels then mean arterial pressure would have dropped at least to 75-77 mmHg in our experimental conditions. It is concluded that skeletal muscle vascular conductance is restrained during whole body exercise in the upright position to avoid hypotension.

  • 4.
    Fuchi, Tokio
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Hickner, R C
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henricksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Microdialysis of rat skeletal muscle and adipose tissue: dynamics of the interstitial glucose pool.1994In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 151, no 2, p. 249-60Article in journal (Refereed)
    Abstract [en]

    Microdialysis was evaluated as a method for studying glucose metabolism in skeletal muscle. Dialysis probes (0.5 x 10 mm) were perfused at 0.5 or 1.0 microliter min-1. Based upon perfusion with glucose, the muscle interstitial glucose concentration was estimated to be 6.9 +/- 0.3 mM (n = 14), which was not significantly different from the blood glucose level. With insulin infusion (1200 mU kg-1 body wt i.v.), the insulin-induced change in the glucose concentration of the interstitial space of muscle was of equal magnitude to that of blood and adipose tissue. In spite of this, when the perfusion medium was not supplemented with glucose, the glucose concentration decreased more in skeletal muscle dialysates (to 36.7 +/- 4.9% of the initial level) than in blood (to 29.7 +/- 5.0%) but less than in adipose tissue (to 17.7 +/- 4.9% of the initial level) (P < 0.05). The results indicate that these differences are due to tissue-specific differences in the dynamic balance between the supply to, and removal from, the interstitial glucose pool. This balance is revealed as a result of the constant glucose drainage by the microdialysis probe. The present results show that, in skeletal muscle, increases in glucose uptake occur with a concomitant increase in tissue blood flow as revealed by the microdialysis ethanol technique, whereas in adipose tissue the glucose uptake increases in the absence of a corresponding increase in blood flow.

  • 5.
    Grigorenko, Anatoli
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Bjerkefors, Anna
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    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).
    Hultling, Claes
    Alm, Marie
    Thorstensson, Alf
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Sitting balance and effects of kayak training in paraplegics.2004In: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 36, no 3, p. 110-6Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: The objectives of this study were to evaluate biomechanical variables related to balance control in sitting, and the effects of kayak training, in individuals with spinal cord injury. SUBJECTS: Twelve individuals with spinal cord injury were investigated before and after an 8-week training period in open sea kayaking, and 12 able-bodied subjects, who did not train, served as controls. METHODS: Standard deviation and mean velocity of centre of pressure displacement, and median frequency of centre of pressure acceleration were measured in quiet sitting in a special chair mounted on a force plate. RESULTS: All variables differed between the group with spinal cord injury, before training, and the controls; standard deviation being higher and mean velocity and median frequency lower in individuals with spinal cord injury. A significant training effect was seen only as a lowering of median frequency. CONCLUSION: The results indicate that individuals with spinal cord injury may have acquired and consolidated an alternative strategy for balance control in quiet sitting allowing for only limited further adaptation even with such a vigorous training stimulus as kayaking.

  • 6.
    Hamrin, Kerstin
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Microdialysis in human skeletal muscle: effects of adding a colloid to the perfusate.2002In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 92, no 1, p. 385-93Article in journal (Refereed)
    Abstract [en]

    Microdialysis catheters (CMA-60 with a polyamide dialysis membrane; 20,000-molecular wt cutoff) were either immersed in an external medium or were inserted in the quadriceps femoris muscle of healthy subjects, using perfusate with or without dextran 70. Varying the position of the outflow tubing induced changes in hydrostatic pressure. The sample volumes were significantly smaller in catheters perfused without a colloid compared with those perfused with a colloid [11-50% (in vitro) and 8-59% (in vivo) lower than in colloid-perfused catheters with the same position of the outflow tubing]. The sample volumes were also significantly smaller when the dialysis membrane was influenced by maximal hydrostatic pressure (above position) compared with minimal hydrostatic pressure (below position) [7-38% (in vitro) and 3-46% (in vivo) lower than in catheters in the below position with the same perfusion fluid]. In vivo, glucose concentration at a perfusion flow rate of 0.33 microl/min was higher when the catheters were perfused without a colloid [18-28% higher than in colloid-perfused catheters with the same position of the outflow tubing (P < 0.001)] than with a colloid. A corresponding difference also tended to occur with lactate, glycerol, and urea. At 0.16 microl/min, the glucose concentration was the same irrespective of whether fluid loss had been counteracted by colloid inclusion or by lowering of outlet tubing. The mechanism behind the observed concentration difference is thought to be a higher effective perfusion flow rate when fluid loss is prevented at low-perfusion flows. This study shows that fluid imbalances can have important implications for microdialysis results at low-perfusion flow rates.

  • 7.
    Henriksson, Jan
    et al.
    Inst. för fysiologi och farmakologi, Karolinska Institutet.
    Hickner, R C
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Fuchi, Tokio
    Oshida, Y
    Jorfeldt, Lennart
    Current trends in microdialysis with focus on the in vivo study of skeletal muscle glucose metabolism1992In: Integration of Medical and Sport Sciences: proceedings of the 8th International Biochemistry of Exercise Conference, Nagoya, September 24-28, 1991, Basel: Karger , 1992, p. 262-272Chapter in book (Other academic)
  • 8. Henriksson, Jan
    et al.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Wallberg, Harriet
    Per-Olof Åstrand: Nekrolog2015Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Nekrolog över Per-Olof Åstrand

    Professor emeritus Per-Olof Åstrand har avlidit i en ålder av 92 år. Hans närmaste anhöriga är makan Irma och barnen Elin och Per med familjer.

    Per-Olof Åstrand föddes i Bredaryd i Småland den 21 oktober 1922, och avled den 2 januari 2015 i Näsby Park norr om Stockholm. Efter värnplikt och beredskapstjänstgöring i pansartrupperna under andra världskriget kom han 1944 till Kungl. Gymnastiska Centralinstitutet (GCI/GIH) för studier till gymnastiklärare. Vid sluttentamen i fysiologi var hans svar så avancerade att den ansvarige läraren bad professorn, Erik Hohwü Christensen, att rätta dem. Kort därefter fick GCI:s fysiologiska institution en ny amanuens.

    Efter gymnastikdirektörsexamen 1946 följde läkarstudier, och parallellt med dessa inleddes avhandlingsarbetet  ”Experimental studies of physical working capacity in relation to sex and age”, som försvarades 1952. Genom detta utvecklades en metodik för att mäta maximal syreupptagning. Det blev en avgörande variabel att relatera till i hans senare forskning om den cirkulatoriska och respiratoriska anpassningen till fysiskt arbete och träning. Det submaximala konditionstest som P.-O., och hans blivande hustru Irma Ryhming, publicerade år 1954 bidrog till att göra GCI känt över världen. Det finns fog att benämna honom som ”den vetenskapligt baserade konditionsträningens fader”. 1970 blev han professor i kroppsövningarnas fysiologi vid GIH.

    P.-O. visade tidigt ett stort intresse för undervisning, och många mötte honom i populärvetenskapliga skrifter såsom ”Kondition och hälsa” och ”Bättre kondition”, men det var genom den omfattande läroboken ”Textbook of Work Physiology: Physiological Bases for Exercise”, skriven tillsammans med Kaare Rodahl, som han blev det riktigt stora namnet inom internationell arbetsfysiologi. Där framträdde holisten Åstrand med en bredd och ett djup som ingen förr hade fångat och skrivit fram. Denna bok, P.-O:s pedagogiska förmåga och engagemang har haft avgörande betydelse för många studenter och kolleger.

    Hans gärningar gjorde honom till ledamot i många lärda sällskap och hedersdoktor vid ett antal universitet ute i världen. Därtill var han en hedersman, med en personlighet präglad av en stor omtanke, slagkraftig humor och generös spiritualitet, ofta med inslag av en särpräglad musikalisk förmåga. För oss som studenter och lärare vid GIH kom samvaron med P.-O. ofta att formas till högtidsstunder. En legendar har nu lämnat oss i djupaste sorg, men också i tacksamhet över allt han bidrog med i våra liv.

    Jan Henriksson

    Hans Rosdahl

    Peter Schantz

    Harriet Wallberg

  • 9.
    Hickner, R C
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Borg, Ingrid
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Jorfeldt, Lennart
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ethanol may be used with the microdialysis technique to monitor blood flow changes in skeletal muscle: dialysate glucose concentration is blood-flow-dependent.1991In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 143, no 3, p. 355-6Article in journal (Refereed)
  • 10.
    Hickner, R C
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Borg, Ingrid
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Jorfeldt, Lennart
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    The ethanol technique of monitoring local blood flow changes in rat skeletal muscle: implications for microdialysis.1992In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 146, no 1, p. 87-97Article in journal (Refereed)
    Abstract [en]

    We have investigated the feasibility of monitoring local skeletal muscle blood flow in the rat by including ethanol in the perfusion medium passing through a microdialysis probe placed in muscle tissue. Ethanol at 5, 55, or 1100 mM did not directly influence local muscle metabolism, as measured by dialysate glucose, lactate, and glycerol concentrations. The clearance of ethanol from the perfusion medium can be described by the outflow/inflow ratio ([ethanol]collected dialysate/[ethanol]infused perfusion medium), which was found to be similar (between 0.36 and 0.38) at all ethanol perfusion concentrations studied. With probes inserted in a flow-chamber, this ratio changed in a flow-dependent way in the external flow range of 5-20 microliters min-1. The ethanol outflow/inflow ratio in vivo was significantly (P less than 0.001) increased (to a maximum of 127 +/- 2.8% and 144 +/- 7.4% of the baseline, mean +/- SEM) when blood flow was reduced by either leg constriction or local vasopressin administration, and significantly (P less than 0.001) reduced (to 62 +/- 6.4% and 43 +/- 4.4% of baseline) with increases in blood flow during external heating or local 2-chloroadenosine administration, respectively. Dialysate glucose concentrations correlated negatively with the ethanol outflow/inflow ratio (P less than 0.01) and consequently decreased (to 46 +/- 7.6% and 56 +/- 5.6% of baseline) with constriction and vasopressin administration and increased (to 169 +/- 32.5% and 262 +/- 16.7% of baseline) following heating and 2-chloroadenosine administration. Dialysate lactate concentrations were significantly increased (approximately 2-fold, P less than 0.001) during all perturbations of blood flow. In conclusion, this technique makes it possible to monitor changes in skeletal muscle blood flow; however, methods of quantification remain to be established. The fact that blood flow changes were found to significantly affect interstitial glucose and lactate concentrations as revealed by microdialysis indicates that this information is critical in microdialysis experiments.

  • 11.
    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.

  • 12. Lövenheim, Boel
    et al.
    Johansson, Christer
    Wahlgren, Lina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment. Riksidrottsförbundet.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Almström, Peter
    Berglund, Svante
    Markstedt, Anders
    Nilsson Sommar, Johan
    Forsberg, Bertil
    Health risk assessment of reduced air pollution exposure when changing commuting by car to bike2016Conference paper (Refereed)
    Abstract [en]

    In this study we have assessed the reduction in traffic emissions and population exposure assuming all potential car commuters would switch to biking if they live within 30 minute travel by bike. The scenario would result in more than 100 000 new bikers and due to the reduced traffic emissions 42 premature deaths would be avoided per year. This is almost twice as large effect as the congestion tax in Stockholm.

     

     

    Introduction

    Regular physical activity has important and wide-ranging health benefits including reduced risk of chronic disease, and physical inactivity is mentioned as perhaps the most important public health problem of the 21st century. At the same time, the direct effects of traffic emissions is a major health problem. Transferring commuting by car to bike will increase physical activity and reduce emissions and reduce population exposure to traffic pollution. The exposure of commuters will also change; new bikers may get higher exposure whilst old bikers and car drivers may get lower exposures, depending on commuting route and distance.

     

    Methodology

    In this study we have calculated the potential number of car-to-bike switching commuters depending on distance, travel time, age of commuters, etc. We have made calculations for a 30-minute biking scenario, i.e. transferring all car commuters to bike if their travel time by bike is less than or equal to 30 minutes. The commuting distance depends on age and sex. For the travel and traffic modelling the LuTrans model was used. It includes all different modes of travel; walking, bicycling, public transport systems and car traffic. The model was developed based on travel survey data and is regularly calibrated using traffic counts. Emissions from road traffic were calculated based on HBEFA 3.2. A Gaussian dispersion model was used estimate exposures over the county of Stockholm.

     

    Results

    The 30 min scenario resulted in 106 881 more bikers, an increase of 2.6 times compared to base scenario. Of all bikers 50% were men and the mean age of all bikers was 42. The traffic emissions of NOx was reduced by up to 7%. Up to 20% reduction in traffic contribution to NOx concentrations was calculated as shown in Figure 1. The mean reduction in concentration for the whole area is 6% and the largest occur were most people live.

    The population weighted mean NOx concentration for 1.6 million people in Greater Stockholm is estimated to be reduced by 0.41 μg m-3. Assuming that the premature mortality is reduced by 8% per 10 μg m-3 (Nafstad et al., 2004), this corresponds to 42 avoided premature deaths every year or 514 gained life years gained. This is even somewhat more beneficial than the effects of the congestion charge in Stockholm (Johansson et al., 2009), which was estimated to save 27 premature deaths per year. The gain in reduced mortality is almost as large as the gain in health of the increased physical activity.

     

    Conclusions

    Transferring car commuters to bike is not only beneficial for the physical activity, but will also lead to reduced traffic emissions and reduced population exposure. Our estimates show that it may be even more beneficial for mortality due to air pollution exposure than the congestion charge in Stockholm.

     

    Acknowledgement

    This project was funded by the Swedish Research Council for Health, Working life and Welfare.

     

    References

    Johansson, C., Burman, L., Forsberg, B. 2009. The effects of congestions tax on air quality and health. Atmos. Environ. 43, 4843-4854.

    Nafstad, P., Lund Håheim, L., Wisloeff, T., Gram, G., Oftedal, B., Holme, I., Hjermann, I. and Leren, P. 2004. Urban Air Pollution and Mortality in a Cohort of Norwegian Men. Environ. Health Perspect. 112, 610-615.

  • 13.
    Nilsson, Johnny E
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Rosdahl, Hans G
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Contribution of Leg Muscle Forces to Paddle Force and Kayak Speed During Maximal Effort Flat-Water Paddling.2016In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 11, no 1, p. 22-27Article in journal (Refereed)
    Abstract [en]

    The purpose was to investigate the contribution of leg-muscle-generated forces to paddle force and kayak speed during maximal-effort flat-water paddling. Five elite male kayakers at national and international level participated. The participants warmed up at progressively increasing speeds and then performed a maximal-effort, non-restricted, paddling sequence. This was followed after five minutes' rest by a maximal-effort paddling sequence with the leg action restricted i.e. the knee joints "locked". Left- and right-side foot-bar and paddle forces were recorded with specially designed force devices. In addition, knee angular displacement of the right and left knee was recorded with electrogoniometric technique and the kayak speed was calculated from GPS signals sampled at 5Hz. The results showed that reduction in both push and pull foot-bar forces resulted in a reduction of 21% and 16% in mean paddle stroke force and kayak mean speed, respectively. Thus, the contribution of foot-bar force from lower limb action significantly contributes to the kayakers paddling performance.

  • 14.
    Nilsson, Johnny E
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Rosdahl, Hans G
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    New Devices for Measuring Forces on the Kayak Foot-Bar and on the Seat During Flat-Water Kayak Paddling: a technical report.2014In: International Journal of Sports Physiology and Performance, ISSN 1555-0265, E-ISSN 1555-0273, Vol. 9, no 2, p. 365-70Article in journal (Refereed)
    Abstract [en]

    The purpose was to develop and validate portable force-measurement devices for recordings of push and pull forces applied by each foot to the foot-bar of a kayak, and the horizontal force at the seat. A foot-plate on a single-point force transducer mounted on the kayak foot-bar underneath each foot allowed the push and pull forces to be recorded. Two metal frames interconnected with four linear ball-bearings and a force transducer allowed recording of horizontal seat force. The foot-bar force device was calibrated by loading each foot plate with weights in the push pull direction perpendicular to the foot plate surface while the seat force device was calibrated to horizontal forces with and without weights on the seat. A strong linearity (r2=0.99-1.0) was found between transducer output signal and load force in the push and pull directions for both foot-bar transducers perpendicular to the foot plate and the seat-force measuring device. Reliability of both devices was tested by means of a test-retest design. The coefficient of variation (CV) for foot-bar push and pull forces ranged from 0.1 to 1.1% and the CV for the seat forces varied between 0.6 - 2.2%. The present study opens up for new investigations of the forces generated within the kayak and ways to optimize kayak paddling performance.

  • 15.
    Rosdahl, Hans
    Inst. för fysiologi och farmakologi, Karolinska Institutet.
    Microdialysis sampling from skeletal muscle and adipose tissue with special reference to the effects of insulin on tissue blood flow and glucose metabolism1998Doctoral thesis, comprehensive summary (Other academic)
  • 16.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Studier av ämnesomsättning och blodflöde i skelettmuskulatur och fettväv1998In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, no 3, p. 46-51Article in journal (Other academic)
  • 17.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Calbet, Jose
    University of Las Palmas de Gran Canaria, Spain.
    Sheel, A. William
    University of British Columbia, Vancouver, Canada.
    Boushel, Robert
    University of British Columbia, Vancouver, Canada.
    Physiology of canoeing2019In: Canoeing / [ed] Don McKenzie, Bo Berglund, Hoboken, NJ: Wiley-Blackwell, 2019, 1, p. 47-61Chapter in book (Other academic)
  • 18.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV). Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Gullstrand, Lennart
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Johansson, Patrik
    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.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method.2010In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 109, no 2, p. 159-171Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate two versions of the Oxycon Mobile portable metabolic system (OMPS1 and OMPS2) in a wide range of oxygen uptake, using the Douglas bag method (DBM) as criterion method. The metabolic variables VO2, VCO2, respiratory exchange ratio and VE were measured during submaximal and maximal cycle ergometer exercise with sedentary, moderately trained individuals and athletes as participants. Test-retest reliability was investigated using the OMPS1. The coefficients of variation varied between 2 and 7% for the metabolic parameters measured at different work rates and resembled those obtained with the DBM. With the OMPS1, systematic errors were found in the determination of VO2 and VCO2. At submaximal work rates VO2 was 6-14% and VCO2 5-9% higher than with the DBM. At VO2max both VO2 and VCO2 were slightly lower as compared to DBM (-4.1 and -2.8% respectively). With OMPS2, VO2 was determined accurately within a wide measurement range (about 1-5.5 L min(-1)), while VCO2 was overestimated (3-7%). VE was accurate at submaximal work rates with both OMPS1 and OMPS2, whereas underestimations (4-8%) were noted at VO2max. The present study is the first to demonstrate that a wide range of VO2 can be measured accurately with the Oxycon Mobile portable metabolic system (second generation). Future investigations are suggested to clarify reasons for the small errors noted for VE and VCO2 versus the Douglas bag measurements, and also to gain knowledge of the performance of the device under applied and non-laboratory conditions.

  • 19.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Hamrin, Kerstin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    A microdialysis method for the in situ investigation of the action of large peptide molecules in human skeletal muscle: detection of local metabolic effects of insulin.2000In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 28, no 1, p. 69-73Article in journal (Refereed)
    Abstract [en]

    The possibility of using microdialysis catheters with a large pore size dialysis membrane (100 kDa) to investigate the action of macromolecules perfused into the interstitial space of peripheral tissues was explored. This was made possible by increasing the colloid osmotic pressure of the perfusate with 40 g/l of dextran-70 to prevent perfusate loss across the dialysis membranes. Microdialysis catheters were inserted into the quadriceps femoris muscle of 13 human subjects. With different perfusion flow rates (1. 33, 0.66, 0.33 and 0.16 microl/min) the recorded concentrations of glucose, lactate, and urea were in agreement with values previously obtained using a conventional membrane with a smaller pore size (20 kDa) [Rosdahl H, Hamrin K, Ungerstedt U, Henriksson. J Am J Physiol 1998;274:E936-45.]. When insulin was added to the perfusate, the concentration of glucose was significantly reduced, indicating that insulin diffuses across the dialysis membrane and has cellular effects that can be simultaneously recorded. The present findings are the first documentation on the use of microdialysis to study the local metabolic action of large peptide molecules in human tissues and may open new avenues for in-vivo metabolic research.

  • 20.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Hamrin, Kerstin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Effect of adding a colloid to the perfusate on net fluid transport across the microdialysis membrane and on concentrations of metabolites in dialysate.Manuscript (preprint) (Other academic)
  • 21.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Hamrin, Kerstin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Insulin perfused through a microdialysis catheter with a 100 KDa dialysis membrane induces local metabolic effects in skeletal muscle.Manuscript (preprint) (Other academic)
  • 22.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Hamrin, Kerstin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Metabolite levels in human skeletal muscle and adipose tissue studied with microdialysis at low perfusion flow.1998In: The American journal of physiology, ISSN 0002-9513, Vol. 274, no 5 Pt 1, p. E936-45Article in journal (Refereed)
    Abstract [en]

    To identify a perfusion flow at which the interstitial fluid completely equilibrates with the microdialysis perfusion fluid, a protocol with successively lower perfusion flows was used. A colloid was included in the perfusion fluid to make sampling possible at the lowest perfusion flows. At 0.16 microliter/min, the measured metabolites had reached a complete equilibration in both tissues, and the measured concentrations of glucose, glycerol, and urea were in good agreement with expected tissue-specific levels. The glucose concentration in adipose tissue (4.98 +/- 0.14 mM) was equal to that of plasma (5.07 +/- 0.07 mM), whereas the concentration in muscle (4.41 +/- 0.11 mM) was lower than in plasma and adipose tissue (P < 0.001). The concentration of lactate was higher (P < 0.001) in muscle (2.39 +/- 0.22 mM) than in adipose tissue (1.30 +/- 0.12 mM), whereas the glycerol concentration in adipose tissue (233 +/- 19.7 microM) was higher (P < 0.001) than in muscle (40.8 +/- 3.0 microM) and in plasma (68.7 +/- 3.97 microM). The concentration of urea was equal in the two tissues. Overall, the study indicates that microdialysis at a low perfusion flow may be a tool to continuously monitor tissue interstitial concentrations.

  • 23.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Lind, Lars
    Millgård, Jonas
    Lithell, Hans
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Effect of physiological hyperinsulinemia on blood flow and interstitial glucose concentration in human skeletal muscle and adipose tissue studied by microdialysis.1998In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 47, no 8, p. 1296-301Article in journal (Refereed)
    Abstract [en]

    The effect of an euglycemic-hyperinsulinemic glucose clamp (94 +/- 5 microU/ml) on blood flow and glucose extraction fraction in human skeletal muscle and adipose tissue was investigated. Limb blood flow was measured by venous occlusion pletysmography and tissue blood flow by the microdialysis ethanol technique. Insulin infusion resulted in an increased blood flow in the calf and forearm (64 and 36%, respectively; P < 0.01) but not in the studied muscles of these limbs (ethanol outflow-to-inflow ratio: m. gastrocnemius 0.144 +/- 0.009 to 0.140 +/- 0.011, NS; m. brachioradialis 0.159 +/- 0.025 to 0.168 +/- 0.027, NS). This was accompanied by an increased extraction fraction of glucose, as measured by an increased arteriovenous difference over the forearm (0.16 +/- 0.04 to 0.70 +/- 0.10 mmol/l; P < 0.001) and by an increase in the estimated arterial-interstitial glucose difference in the gastrocnemius (0.82-1.42 mmol/l) and brachioradialis muscle (0.82-1.97 mmol/l). The blood flow in adipose tissue was significantly increased during insulin infusion, as evidenced by a decreased ethanol outflow-to-inflow ratio (0.369 +/- 0.048 to 0.325 +/- 0.046; P < 0.01). This was accompanied by an unchanged concentration of glucose in the dialysate (-2.6%, NS). In summary, during physiological hyperinsulinemia 1) a blood flow increase was detected in the calf and forearm, but not in the studied muscles of these limbs; 2) the blood flow increased in the subcutaneous adipose tissue; and 3) the estimated arterial-interstitial glucose difference increased in both muscles studied and was larger in the forearm muscle than the arteriovenous glucose difference over the forearm. The present study shows that microdialysis is a useful tool to obtain tissue-specific information about the effect of insulin on blood flow and glucose extraction in human skeletal muscle and adipose tissue.

  • 24.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Lindberg, Thomas
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Edin, Fredrik
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    The Moxus Modular metabolic sustem evaluated with two sensors for ventilation against the Douglas bag method2013In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, no 5, p. 1353-1367Article in journal (Refereed)
    Abstract [en]

    This study evaluated the Moxus metabolic system with the Douglas bag method (DBM) as criterion. Reliability and validity were investigated in a wide range of ventilation and oxygen uptake and two sensors for determining ventilation were included. Thirteen well-trained athletes participated in one pre-test and four tests for data collection, exercising on a cycle ergometer at five submaximal powers (50-263 W) and at [Formula: see text]. Gas exchange variables were measured simultaneously using a serial setup with data collected on different days in an order randomized between Moxus with pneumotachometer (MP) and turbine flowmeter (MT) sensors for ventilation. Reliability with both sensors was comparable to the DBM. Average CV (%) of all exercise intensities were with MP: 3.0 ± 1.3 for VO(2), 3.8 ± 1.5 for VCO(2), 3.1 ± 1.2 for the respiratory exchange ratio (RER) and 4.2 ± 0.8 for V (E). The corresponding values with MT were: 2.7 ± 0.3 for VO(2), 4.7 ± 0.4 for VCO(2), 3.3 ± 0.9 for RER and 4.8 ± 1.4 for V (E). Validity was acceptable except for small differences related to the determination of ventilation. The relative differences in relation to DBM at the powers including [Formula: see text] were similar for both sensors with the ranges being: +4 to -2 % for V (E), +5 to -3 % for VO(2) and +5 to -4 % for VCO(2) while RER did not differ at any power. The Moxus metabolic system shows high and adequate reliability and reasonable validity over a wide measurement range. At a few exercise levels, V (E) differed slightly from DBM, resulting in concomitant changes in VO(2) and VCO(2).

  • 25.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Contribution of leg muscle forces to paddle stroke force and kayak speed during maximal effort flat-water paddling among elite kayakers2015In: Book of abstracts: 20th annual Congress of the European College of Sport Science, ECSS Malmö 2015, 2015, p. 318-319Conference paper (Other academic)
  • 26.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Validation of data collected with mobile metabolic measurement systems over time during active commuting2016Conference paper (Refereed)
    Abstract [en]

    Introduction

    With the aim of attaining valid descriptions of metabolic demands during active commuting in greater Stockholm new approaches have been used. We have previously reported evaluations of a mobile metabolic measurement system both in the laboratory (Rosdahl et al. 2010) and during simulated field conditions, including check of stability over time (Salier-Eriksson et al. 2012). However, to be confident with the validity of the metabolic data collected over time during mobile field conditions we have used new approaches. 

    Methods

    During the period of data collection in the field with the mobile metabolic system (Oxycon Mobile, JLAB 5.21, CareFusion, Germany) this was controlled once by the manufacturer and 11 times in our own laboratory using a commercially available metabolic calibrator (Vacumed, syringe No.1750 and mass flow controller No. 17052, Ventura, CA, USA).  On each occasion VO2 and VCO2 were checked between 1 - 4 L/min with the corresponding VE at 40-160 L/minute and tidal volume at 2 L. The calibration information (offset, gain and delay time) from the O2 and CO2 analyzers and volume sensor, being collected pre and post the field commuting tests, was analyzed. Additionally, the results of each experiment was critically examined in several means including an inspection of parallelism in heart rate and VO2. 

    Results and Discussion

    As examined with the metabolic calibrator, all parameters (VO2, VCO2, RER and VE) measured by the mobile metabolic system were in general well within the boundaries of acceptance. Adequate stability of the O2 and CO2 analyzers and volume sensors for the time duration of each experiment was confirmed by small differences in the pre- and post-calibration factors. Based on two researchers´ ocular inspections of heart rate and oxygen uptake recordings during active commuting, all but one were rated as generally parallel, and thus passed this type of check of the field measurements. Overall, the present investigation favors that data collected over time with a mobile metabolic system can be validated by a combination of metabolic calibrator measurements, analyses of calibration information and a critical examination of the variables from each single measurement.

    References

    Rosdahl, H., Gullstrand, L., Salier Eriksson, J., Johansson, P. & Schantz, P. 2010. Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method. Eur J Appl Physiol 109 (2):159-71.

    Salier Eriksson, J., Rosdahl, H. & Schantz, P. 2012. Validity of the Oxycon Mobile metabolic system under field measuring conditions. Eur J Appl Physiol, 112 (1): 345-355.

    Huszczuk, A., Whipp, B.J and Wasserman, K. 1990. A respiratory gas exchange simulator for routine calibration in metabolic studies. Eur. Respir. J. 3:465-468.

  • 27.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Salier-Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Measurements of Metabolic Profiles of Commuting Pedestrians and Cyclists using Validated Indirect Calorimetry2010In: Proceedings from The 3rd International Congress on Physical Activity and Public Health, Toronto, May, 5-8, 2010, 2010, p. 36-Conference paper (Other academic)
  • 28.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Samuelsson, A C
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Influence of adrenergic agonists on the release of amino acids from rat skeletal muscle studied by microdialysis.1998In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 163, no 4, p. 349-60Article in journal (Refereed)
    Abstract [en]

    The microdialysis technique was used to study the effects of adrenergic agonists on the release of amino acids from rat skeletal muscle. The release was monitored indirectly by measurements of interstitial concentrations. To distinguish metabolic from vasoactive effects, the adrenaline and isoprenaline results were compared with those of vasopressin, alpha-agonists and adenosine. As determined by the microdialysis ethanol technique, adrenaline, alpha-agonists and vasopressin induced vasoconstriction, whereas isoprenaline and adenosine induced vasodilatation. The lactate-to-pyruvate ratio increased fourfold with adrenaline (P < 0.001) and by 54% with isoprenaline (P < 0.05), whereas no change was observed with alpha-agonists and adenosine. Vasopressin induced a fivefold increase in the lactate-to-pyruvate ratio (P < 0.001), but with an unchanged pyruvate concentration, indicating that the effect may have been secondary to ischaemia. Adrenaline induced a twofold and vasopressin a 34% increase in the concentration of alanine (P < 0.001), whereas isoprenaline, adenosine and alpha-agonists had no significant effect. Adrenaline-perfusion induced an initial anabolic effect as evidenced by a reduced concentration of tyrosine. A significant decrease in the glutamate-to-glutamine ratio was observed with adrenaline and isoprenaline (22 and 27%, P < 0.01) whereas alpha-agonists, vasopressin and adenosine were without effect. In conclusion, the present study showed that adrenaline, via a beta-adrenergically mediated activation of glycogenolysis, possibly further stimulated by ischaemia, induced an increased release of alanine from skeletal muscle. The study indicates a beta-adrenergic stimulation on the glutamine synthetase step and a short lasting anabolic effect of adrenaline. Differences in the magnitude of the effects of adrenaline and isoprenaline could be related to their different vasoactive properties.

  • 29.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Sundqvist, Kalle
    Svenska Kanotförbundet.
    Kraftmätning ett forskningsprojekt: kan trådtöjningsgivare och datateknik användas för att effektivisera paddelteknik?1997In: Kanot Nytt, ISSN 0022-8397, no 3, p. 5-9Article in journal (Other (popular science, discussion, etc.))
  • 30.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Microdialysis in human skeletal muscle and adipose tissue at low flow rates is possible if dextran-70 is added to prevent loss of perfusion fluid.1997In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 159, no 3, p. 261-2Article in journal (Refereed)
  • 31.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ungerstedt, Urban
    Jorfeldt, Lennart
    Henriksson, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Interstitial glucose and lactate balance in human skeletal muscle and adipose tissue studied by microdialysis.1993In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 471, p. 637-57Article in journal (Refereed)
    Abstract [en]

    1. Microdialysis was used to gain insight into the substrate exchanges in the interstitial space of skeletal muscle and adipose tissue. Probes were inserted in the quadriceps femoris muscle and para-umbilical subcutaneous adipose tissue of thirteen subjects and microdialysis was performed at different flow rates (1-4 microliters min-1) and during changes in tissue blood flow. 2. When ethanol (5 mM) is included in the perfusion solution, the ethanol clearance from the probe is a measure of tissue blood flow. Blood flow changes induced by adenosine or vasopressin perfusion, by exercise or by circulatory occlusion resulted in ethanol clearance values of 69-139% of the basal level. The ethanol clearance was higher in skeletal muscle than in adipose tissue (32-62%, P < 0.001), a difference compatible with a higher blood flow in muscle tissue. 3. The fraction of the interstitial glucose concentration that was recovered with the microdialysis was similar in skeletal muscle (the absolute values being 1.70 +/- 0.14 mM at 1 microliter min-1 and 0.59 +/- 0.05 mM at 4 microliters min-1) and adipose tissue (1.89 +/- 0.20 mM at 1 microliter min-1; 0.54 +/- 0.05 mM at 4 microliters min-1) and correlated inversely with the tissue ethanol clearance, both in the basal state and during changes in tissue blood flow (muscle: r = -0.56 to -0.67; adipose tissue r = -0.72 to -0.95). Coefficients of variation were 6-8% (glucose) and 11-16% (lactate) and were similar during isometric exercise. The reproducibility of the technique (comparison of two contralateral probes; perfusion flow rate 4 microliters min-1) was 5.3-8.3% (ethanol) and 23.9-20.8% (glucose) in muscle (n = 6) and adipose tissue (n = 4) respectively. 4. The skeletal muscle dialysate lactate concentration (1 microliter min-1: 1.16 +/- 0.2 mM) was higher than in adipose tissue (0.76 +/- 0.08 mM, P < 0.05), where the absolute amount of lactate that could be removed from the tissue (at 4 microliters min-1) was only half of that in skeletal muscle (0.8 +/- 0.11 vs. 1.76 +/- 0.23 nmol min-1, P < 0.05). The dialysate lactate level was not affected in either tissue by large changes in the interstitial glucose concentration indicating that in neither tissue is blood glucose a significant source of lactate formation. 5. The blood flow effects on the dialysate glucose concentration are the likely consequence of probe glucose drainage artificially shifting the balance between the supply and consumption of interstitial glucose.(ABSTRACT TRUNCATED AT 400 WORDS)

  • 32.
    Salier Eriksson, Jane
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Is the heart rate method for estimating oxygen consumption valid in cycle commuting?Manuscript (preprint) (Other academic)
  • 33.
    Salier Eriksson, Jane
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Is the heart rate method for estimating oxygen consumption valid in walking commuting?Manuscript (preprint) (Other academic)
  • 34.
    Salier Eriksson, Jane
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Relationships between heart rate and oxygen uptake in laboratory conditions and in bicycling commuting2016Conference paper (Refereed)
    Abstract [en]

    Introduction. Measuring the energetic demands of habitual commuter cyclists is essential to create more accurate methods for measuring active commuting so as to be able to objectively determine the impact that cycle commuting can have on population health.

    Heart rate (HR) can be used as an indicator of aerobic processes while commuter cycling as long as the relationship between oxygen uptake (VO2) and HR is established in laboratory conditions. However in the field, environmental aspects might introduce effects of stress that change the relationship. Thus measurements need also to be performed in the field in order to explore the HR-VO2 relationship between the two conditions.

    Methods. Metabolic measurements were performed in the laboratory as well as in the field using 20 habitual commuter cyclists (10 males and 10 females) aged 44 ± 3 yrs. A validated stationary as well as a portable metabolic system was used (Rosdahl et al. 2010; 2016; Salier-Eriksson et al. 2012). A comparison was made between the laboratory and field conditions of the HR-VO2 relationship.

    Results and Discussion. Based on the average heart rate, the measured oxygen uptake was about 2.5 % lower (n.s.) than the expected levels based on the steady state HR-VO2 relationships in the laboratory. Thus, the results indicate that the HR-VO2 relationships in the field were comparable to those measured in the laboratory on a group level. However, relatively large individual differences were found.

    References

    Rosdahl, H., Gullstrand, L., Salier Eriksson, J., Johansson, P. & Schantz, P. 2010. Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method. Eur J Appl Physiol 109 (2):159-71.

    Rosdahl, H., Salier Eriksson, J. & Schantz, P. 2016. Validation of data collected with mobile metabolic measurement systems over time during active commuting. Proceedings of the 21st Annual Congress of The European College of Sport Sciences, Vienna, Austria, 6-8 July (Abstract).  

    Salier Eriksson, J., Rosdahl, H. & Schantz, P. 2012. Validity of the Oxycon Mobile metabolic system under field measuring conditions. Eur J Appl Physiol, 112 (1): 345-355.

     

     

     

  • 35.
    Salier Eriksson, Jane
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Validity of the Oxycon Mobile metabolic system under field measuring conditions2012In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, no 1, p. 345-355Article in journal (Refereed)
    Abstract [en]

    Abstract

    Purpose: It is essential to validate portable metabolic systems, not only in laboratory settings, but also in field measuring conditions, such as prolonged moderate exercise at low temperatures, high humidity and with external wind.

     

    Methods: VO2, VCO2, RER and VE were measured using the Oxycon Mobile (OM), with a windshield, during cycle ergometer exercise: (I) indoors at three submaximal workloads with no wind or with external wind (13–20 m·s-1) from front, side and back; (II) at two submaximal workloads outdoors (12 ± 2oC; 86 ± 7% RH), with and without a system for drying the ambient air around the air sampling tube; and (III) at one workload outdoors for 45 min (5 ± 4oC; 69 ± 16.5% RH). Any physiological drift was checked for with pre- and postmeasurements by the Douglas bag method (DBM).

     

    Results: A minor effect of external wind from behind was noted in RER and VE (-2 and -3%).. The system for drying the ambient air around the gas sampling tube had no effect on the measured levels. A small difference in VCO2 drift between the OM and DBM (1.5 mL·min-2) was noted in the stability test.

     

    Conclusion: Heavy external wind applied from different directions generally does not affect the measurements of the OM. Furthermore, when using a unit for drying the ambient air around the gas sampling tube, the OM can accurately measure VO2, RER and VE   at submaximal workloads for at least45 min under challenging conditions with regard to humidity and temperature.

     

  • 36.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    An Overview, Description and Synthesis of Methodological Issues in Studying Oxygen Consumption during Walking and Cycling Commuting using a Portable Metabolic System (Oxycon Mobile).2018Other (Other academic)
    Abstract [en]

    From the time of the independent discoveries of oxygen by Carl Wilhelm Scheele in Sweden and Joseph Priestly in England in the 1770s, there has been an ongoing chain of methodological developments, from the pioneering ones by Antoine Lavoisier until today, with the aim of measuring oxygen uptake and metabolic processes of man in motion (Mitchell and Saltin 2003). This historical development, has, not least during the last decades, also included both automated stationary and portable open-circuit metabolic measurement systems, which have been thoroughly reviewed recently (Macfarlane 2017; Ward 2018; Taylor et al. 2018).  

    When two of the present authors (PS and HR) were trained as exercise physiologists, the golden standard method in this respect, the Douglas bag method (DBM), was the only, or the predominantly used method at our laboratory. In the 1990s, automated stationary open-circuit metabolic measurement systems started to be used, and HR evaluated some of them using DBM. He noted that it was not apparent that one could rely on the data produced in these “black box” systems. Still they have been used in many laboratories, and possibly there are a number of scientific articles based on them which might hold invalid data. One comment along that line was sent in 2001 as an e-mail from our teacher, professor emeritus Per-Olof Åstrand to an American colleague (Appendix 1). It ended with: “I have observed many odd data in the literature which can be explained as a consequence of uncritical use of modern, fancy electronic equipments without serious and competent evaluation of their accuracy”.

    For HR, these kind of experiences during the 1990s became an important impetus to develop a refined system for the Douglas bag method at the Laboratory for Applied Sport Sciences at the Swedish School for Sport and Health Sciences, GIH, in Stockholm, Sweden. That process was undertaken in close collaboration with Lennart Gullstrand at the Elite Sports Centre, The Swedish Sports Confederation, Bosön, Lidingö, Sweden. This text builds on that system, and many other developmental steps that have been taken since then. They have been applied to study a number of issues related to walking and cycle commuting, as part of the multidisciplinary research project on Physically Active Commuting in Greater Stockholm (PACS) at GIH. For its overall aims, see: www.gih.se/pacs

    One of the aims is to characterize the physiological demands of walking and cycle commuting in relation to absolute and relative demands of oxygen uptake (VO2). This is of interest in itself for understanding the nature of the physical activity during active commuting. Combined with other kinds of data one aim was also to better understand the potential health effects of active commuting. An important issue in this respect was to scrutinize whether the heart rate method for estimating VO2 (Berggren & Hohwü Christensen 1950) would be a reliable and valid method during cycle or walking commuting.

    To reach these goals we needed to use an automated mobile metabolic system. However, we had to work for a much longer time than expected due to a surprising number of diverse methodological challenges in measurements of both VO2 and heart rate (HR). They had to be considered and evaluated through a series of validity studies and checks. Some of the issues could be foreseen and were rather straight forward to handle, whereas others were unexpected, and the strategies to handle them had to be developed step by step as they appeared during the research process. Here this process will be first introduced, then described in more or less detail, and in cases of less details, we instead refer to issues in more depth in original articles. Finally, a synthesis of all studies and their consequences is elaborated on at the end of this appendix.

  • 37.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Can heart rate be used as an indicator of energy demands during commuter walking in a metropolitan area?2016Conference paper (Refereed)
    Abstract [en]

    Introduction

    Measuring the energetic demands of habitual commuter walking is essential to objectively relate to the impact that walking commuting can have on health. Hence, evaluating methods for such purpose is of great importance. Heart rate (HR) can possibly be used as long as the relationship between oxygen uptake (VO2) and HR is established in laboratory conditions and proven to be valid under field conditions. However, e.g. traffic, noise and exhaust fumes may introduce effects of e.g. stress that change the relationship in the field. Thus, the validity of the HR method needs to be scrutinized.

    Methods

    VO2 and HR measurements during three submaximal exercise intensities on cycle ergometer were performed in the laboratory, as well as during normal commuting walking in the individuals´ normal field setting in Greater Stockholm, Sweden. 20 habitual commuter pedestrians (10 males and 10 females) aged 45 ± 7 yrs (mean ± SD) participated and validated stationary and portable metabolic systems (Rosdahl et al. 2010; 2016; Salier-Eriksson et al. 2012), and HR monitors were used. A comparison of the VO2 – HR relationship was made between the laboratory and field conditions.

    Results and Discussion 

    Interpreting the heart rate levels during walking commuting from the VO2 – HR relationship in the laboratory resulted in oxygen uptakes that were 13.0 ± 10.6 % lower in males and 10.5 ± 11.5 % lower in females than the correct VO2 values. Thus, the study indicates that systematic differences between the laboratory and field conditions with respect to the VO2 – HR relationship are present in metropolitan conditions. The reason for these differences remains to be elucidated.

    References

    Rosdahl, H., Gullstrand, L., Salier Eriksson, J., Johansson, P. & Schantz, P. 2010. Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method. Eur J Appl Physiol 109 (2):159-71.

    Rosdahl, H., Salier Eriksson, J. & Schantz, P. 2016. Validation of data collected with mobile metabolic measurement systems over time during active commuting. Proceedings of the 21st Annual Congress of The European College of Sport Sciences, Vienna, Austria, 6-8 July (Abstract).

    Salier Eriksson, J., Rosdahl, H. & Schantz, P. 2012. Validity of the Oxycon Mobile metabolic system under field measuring conditions. Eur J Appl Physiol, 112 (1): 345-355.

  • 38.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    The heart rate method for estimating oxygen uptake: Analyses of reproducibility with heart rates from commuter walkingManuscript (preprint) (Other academic)
  • 39.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    The Heart Rate Method for Estimating Oxygen Uptake: Analyses of Reproducibility Using a Range of Heart Rates from Cycle Commuting2019In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 14, no 7, article id e0219741Article in journal (Refereed)
    Abstract [en]

    Background. Monitoring aerobic exercise intensities of free-living physical activities is valuable for purposes such as education and research. The heart rate (HR) method, based on the linear relation between HR and oxygen uptake (VO2), is potentially valuable for this purpose. Three prerequisites are that the method is reproducible, and valid for the specific form of physical activity executed as well as under field conditions. The aim of this study is to evaluate reproducibility of the heart rate method in the laboratory.

     

    Methods. VO2 and HR measurements were made on two different occasions during three submaximal (model 1) plus a maximal exercise intensity (model 2) on a cycle ergometer in the laboratory. 19 habitual commuter cyclists (9 males and 10 females), aged 44 ± 3 years, were measured. The reproducibility of the estimated VO2, based on three levels of HR from commuting cycling and the regression equations from test and retest were analyzed. Differences between the two models were also studied. 

     

    Results. For both models, there were no significant differences between test and retest in the constituents of the regression equations (y-intercept, slope and r-value). Neither were there any systematic differences in estimated absolute levels of VO2 between test and retest. The relative differences between test and retest, based on estimations from three different levels of HR, were 0.99 ± 11.0 (n.s.), 2.67 ± 6.48 (n.s.) and 3.57 ± 6.24% (p<0.05) for model 1, and 1.09 ± 10.6, 1.75 ± 6.43 and 2.12 ± 5.92% (all n.s.) for model 2. However, some large individual differences were seen in both models. There were no significant differences between the two models in the slopes, intercepts or r-values of the regression equations or in the estimated levels of VO2.

     

    Conclusion. The heart rate method shows good reproducibility on the group level in estimating oxygen consumption from HR-VO2 relations in the laboratory, and based on three levels of HR which are representative for cycle commuting. However, on the individual level, some large variations were seen.

  • 40.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Stigell, Erik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Dang, Phung
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier-Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Kan fysiskt aktiv arbetspendling bli en "folkrörelse"?2006In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, no 3, p. 8-13Article in journal (Other academic)
  • 41.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Wahlgren, Lina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Nilsson Sommar, Johan
    Umeå Universitet.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Estimating duration-distance relations in cycle commuting in the general population2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 11, article id e0207573Article in journal (Refereed)
    Abstract [en]

    It is important to estimate the duration-distance relation in cycle commuting in the general  population since this enables analyses of the potential for various public health outcomes. Therefore, the aim is to estimate this relation in the Swedish adult population of 2015. For that purpose, the first step was to establish it for adult male and female cycle commuters in Greater Stockholm, Sweden. Whether or not the slopes of these relations needed to be altered in order to make them representative of the general population was evaluated by comparing the levels of maximal oxygen uptake in samples of commuter cyclists and the population. The measure used was the maximal oxygen uptake divided by both the body weight and a cycle weight of 18.5 kg. The body weights in the population samples were adjusted to mirror relevant levels in 2015. Age adjustments for the duration–distance relations were calculated on the basis of the maximal oxygen uptake in the population samples aged 20–65 years. The duration-distance relations of the cycle commuters were downscaled by about 24–28% to mirror levels in the general population. The empirical formula for the distance (D, km) was based on duration (T, minutes)  x  speed (km/min)  x  a correction factor from cycle commuter to the general population  x  age adjustment (A, years). For the males in the general population the formula was: D = T  x  20.76 km/h  x  0.719  x  (1.676 – 0.0147  x  A). For females, the  formula was: D = T  x  16.14 km/h  x  0.763  x  (1.604 – 0.0129  x  A). These formulas, combined with distributions of route distances between home and work in the population, enable realistic evaluations of the potential for different public health outcomes through cycle commuting.

  • 42.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Wahlgren, Lina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Vilka folkhälsovinster kan erhållas vid olika scenarier av ökad cykling i en storstadsregion?: Empiri och fysisk arbetskapacitet som grund för beräkning av potentiell cykelpendling.2015Conference paper (Other academic)
    Abstract [sv]

    Vilka folkhälsovinster kan erhållas vid olika scenarier av ökad cykling i en storstadsregion?

    Syfte: Ur såväl transport- och miljö- som folkhälsoperspektiv är det värdefullt att utveckla kunskap om potentialen att överföra bilresor för arbetspendling till cykelresor. Det är också angeläget att belysa hur detta kan leda till ökade nivåer av fysisk aktivitet och förbättrad luftkvalité, samt att analysera vilka hälsokonsekvenser en förbättrad luftkvalité det kan medföra inom hela befolkningen inom en storstadsregion.  

    För detta krävs att vitt skilda kompetenser samverkar. Man behöver till exempel kombinera kunskap om resmönster och färdvägsavstånd för olika kön och ålder, med kunskap om arbetsfysiologisk kapacitet och cyklisters beteende samt hur luftkvaliteten ter sig, hur den kan ändras, och vilka konsekvenser det får.

    Genom ett unikt samarbete mellan Umeå Universitet, Stockholms Universitet, Stockholms miljöförvaltning, Gymnastik- och idrottshögskolan samt konsultföretaget WSP har vitt skilda kompetenser sammanförts för att belysa dessa frågeställningar i ett integrativt forskningsprojekt med Stor-Stockholm som studieområde.  Projektet utvecklar dessutom även ny metodologisk kunskap som är av ett brett intresse för samhälls- och trafikplanering inom storstadsområden.

  • 43.
    Schantz, Peter
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Wahlgren, Lina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Salier-Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Stigell, Erik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Is Active Commuting the answer to Population Health?:  Lessons from the Stockholm Studies (PACS) – A Prologue.2010In: Proceedings from The 3rd International Congress on Physical Activity and Public Health, Toronto, Canada, 2010,, 2010, p. 35-Conference paper (Other academic)
  • 44.
    Van Hall, Gerrit
    et al.
    The Copenhagen Muscle Research Centre, Rigshospitalet, 2200 Copenhagen N, Denmark.
    Jensen-Urstad, Mats
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Holmberg, H-C
    Saltin, Bengt
    Calbet, J A L
    Leg and arm lactate and substrate kinetics during exercise.2003In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 284, no 1, p. E193-205Article in journal (Refereed)
    Abstract [en]

    To study the role of muscle mass and muscle activity on lactate and energy kinetics during exercise, whole body and limb lactate, glucose, and fatty acid fluxes were determined in six elite cross-country skiers during roller-skiing for 40 min with the diagonal stride (Continuous Arm + Leg) followed by 10 min of double poling and diagonal stride at 72-76% maximal O(2) uptake. A high lactate appearance rate (R(a), 184 +/- 17 micromol x kg(-1) x min(-1)) but a low arterial lactate concentration ( approximately 2.5 mmol/l) were observed during Continuous Arm + Leg despite a substantial net lactate release by the arm of approximately 2.1 mmol/min, which was balanced by a similar net lactate uptake by the leg. Whole body and limb lactate oxidation during Continuous Arm + Leg was approximately 45% at rest and approximately 95% of disappearance rate and limb lactate uptake, respectively. Limb lactate kinetics changed multiple times when exercise mode was changed. Whole body glucose and glycerol turnover was unchanged during the different skiing modes; however, limb net glucose uptake changed severalfold. In conclusion, the arterial lactate concentration can be maintained at a relatively low level despite high lactate R(a) during exercise with a large muscle mass because of the large capacity of active skeletal muscle to take up lactate, which is tightly correlated with lactate delivery. The limb lactate uptake during exercise is oxidized at rates far above resting oxygen consumption, implying that lactate uptake and subsequent oxidation are also dependent on an elevated metabolic rate. The relative contribution of whole body and limb lactate oxidation is between 20 and 30% of total carbohydrate oxidation at rest and during exercise under the various conditions. Skeletal muscle can change its limb net glucose uptake severalfold within minutes, causing a redistribution of the available glucose because whole body glucose turnover was unchanged.

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