Time to Exhaustion at V˙O2max is Related to the Lactate Exchange and Removal Abilities

Publisher Website
Google Scholar
Abstract
The aim of the present study was to investigate the relationships between lactate exchange and removal abilities and the capacity to prolong exercise, as assessed by the time to exhaustion (Tlim) at a work rate corresponding to V˙O2max (Pamax). The individual blood lactate recovery curves obtained for 13 untrained subjects after 5 min 90 % Pamax exercise were fitted to the biexponential time function: La(t) = La(0) + A1(1-e-γ1 × t) + A2(1-e-γ2 × t), where t is time into the recovery, La(0) is the arterialized lactate concentration measured at the end of the exercise, γ1 and γ2 are velocity constants denoting the lactate exchange and removal abilities, respectively. Tlim was positively related to γ1 and γ2 (r = 0.60, p < 0.05 and r = 0.56, p < 0.05, respectively) but was negatively related to La(0) (r = 0.75, p < 0.01). γ1 was positively related to the capillary density (r = 0.69, p < 0.01) and to the number of capillaries per type I fiber area (r = 0.62, p < 0.05). It was concluded that 1) high lactate exchange and removal abilities would allow continuing a high-intensity exercise for a longer duration, and 2) a high capillary density may explain the associated high lactate exchange ability.

This publication has 0 references indexed in Scilit: