Exercise performance and V0₂ kinetics during upright and recumbent high-intensity cycling exercise
Data(s) |
01/09/2010
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Resumo |
This study investigated cycling performance and oxygen uptake (VO<sub>2</sub>) kinetics between upright and two commonly used recumbent (R) postures, 65ºR and 30ºR. On three occasions, ten young active males performed three bouts of high-intensity constant-load (85% peak workload achieved during a graded test) cycling in one of the three randomly assigned postures (upright, 65ºR or 30ºR). The first bout was performed to fatigue and second and third bouts were limited to 7 min. A subset of seven subjects performed a final constant-load test to failure in the supine posture. Exercise time to failure was not altered when the body inclination was lowered from the upright (13.1 ± 4.5 min) to 65ºR (10.5 ± 2.7 min) and 30ºR (11.5 ± 4.6 min) postures; but it was significantly shorter in the supine posture (5.8 ± 2.1 min) when compared with the three inclined postures. Resulting kinetic parameters from a tri-exponential analysis of breath-by-breath VO<sub>2</sub> data during the first 7 min of exercise were also not different between the three inclined postures. However, inert gas rebreathing analysis of cardiac output revealed a greater cardiac output and stroke volume in both recumbent postures compared with the upright posture at 30 s into the exercise. These data suggest that increased cardiac function may counteract the reduction of hydrostatic pressure from upright ~25 mmHg; to 65ºR ~22 mmHg; and 30ºR ~18 mmHg such that perfusion of active muscle presumably remains largely unchanged, and also therefore, VO<sub>2</sub> kinetics and performance during high-intensity cycling.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Springer |
Relação |
http://dro.deakin.edu.au/eserv/DU:30030460/warmington-exercise-2010.pdf http://dx.doi.org/10.1007/s00421-010-1466-y |
Direitos |
2010, Springer-Verlag |
Palavras-Chave | #Recumbent #Cycling #Posture #Performance #VO₂ kinetics |
Tipo |
Journal Article |