Blood Lactate Concentration Is Not Related to the Increase in Cardiorespiratory Fitness Induced by High Intensity Interval Training.

Background: There is individual responsiveness to exercise training as not all individuals experience increases in maximal oxygen uptake (VOmax), which does not benefit health status considering the association between VOmax and mortality. Approximately 50% of the training response is genetic, with the other 50% accounted for by variations in dietary intake, sleep, recovery, and the metabolic stress of training. This study examined if the blood lactate (BLa) response to high intensity interval training (HIIT) as well as habitual dietary intake and sleep duration are associated with the resultant change in VOmax (ΔVOmax).

Change in VO and time trial performance in response to high-intensity interval training prescribed using ventilatory threshold.

Unlabelled: Completion of high-intensity interval training (HIIT) leads to significant increases in maximal oxygen uptake (VO) and oxidative capacity. However, individual responses to HIIT have been identified as approximately 20-40% of individuals show no change in VO, which may be due to the relatively homogeneous approach to implementing HIIT.

Purpose: This study tested the effects of HIIT prescribed using ventilatory threshold (VT) on changes in VO and cycling performance.