The highest velocity and the shortest duration permitting attainment of VO2max during running

DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n2p226 The severe-intensity domain has important applications for the prescription of running training and the elaboration of experimental designs. The objectives of this study were: 1) to investigate the validity of a previously proposed model to estimate the shortest exercise duration (TLOW) and the highest velocity (VHIGH) at which VO2max is reached during running, and 2) to evaluate the effects of aerobic training status on these variables. Eight runners and eight physically active subjects performed several treadmill running exercise tests to fatigue in order to mathematically estimate and to experimentally determine TLOW and VHIGH. The relationship between the time to achieve VO2max and time to exhaustion (Tlim) was used to estimate TLOW. VHIGH was estimated using the critical velocity model. VHIGH was assumed to be the highest velocity at which VO2 was equal to or higher than the average VO2max minus one standard deviation. TLOW was defined as Tlim associated with VHIGH. Runners presented better aerobic fitness and higher VHIGH (22.2 ± 1.9 km.h-1) than active subjects (20.0 ± 2.1 km.h-1). However, TLOW did not differ between groups (runners: 101 ± 39 s; active subjects: 100 ± 35 s). TLOW and VHIGH were not well estimated by the model proposed, with high coefficients of variation (> 6%) and a low correlation coefficient (r