title: In humans the oxygen uptake slow component is reduced by prior exercise of high as well as low intensity.
abstract: The aim of the study was to examine to what extent prior high- or low-intensity cycling, yielding the same amount of external work, influenced the oxygen uptake (VO2) slow component of subsequent high-intensity cycling. The 12 subjects cycled in two protocols consisting of an initial 3 min period of unloaded cycling followed by two periods of constant-load exercise separated by 3 min of rest and 3 min of unloaded cycling. In protocol 1 both periods of exercise consisted of 6 min cycling at a work rate corresponding to 90% peak oxygen uptake (VO2peak). Protocol 2 differed from protocol 1 in that the first period of exercise consisted of a mean of 12.1 (SD 0.8) min cycling at a work rate corresponding to 50% VO2peak. The difference between the 3rd min VO2 and the end VO2 (deltaVO2(6-3)) was used as an index of the VO2 slow component. Prior high-intensity exercise significantly reduced deltaVO2(6-3). The deltaVO2(6-3) was also reduced by prior low-intensity exercise despite an unchanged plasma lactate concentration at the start of the second period of exercise. The reduction was more pronounced after prior high- than after prior low-intensity exercise (59% and 28%, respectively). The results of this study show that prior exercise of high as well as low intensity reduces the VO2 slow component and indicate that a metabolic acidosis is not a necessary condition to elicit a reduction in deltaVO2(6-3).
authors.affiliation: Department of Movement and Sports Sciences, University of Ghent, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Koppo
authors.forename: J
authors.initials: J
authors.lastname: Bouckaert
mesh_terms: D000328:Adult; D001642:Bicycling; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007700:Kinetics; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D013997:Time Factors
chemical_list: D019344:Lactic Acid