SLOW-TWITCH FIBER CAPILLARIZATION GOVERNS LACTATE REMOVAL

Messonnier, L., Freund, H., Denis, C., Dormois, D., Dufour, A.-B., & Lacoour, J.-R. (2002). Time to exhaustion at VO2max is related to the lactate exchange and removal abilities. International Journal of Sports Medicine, 23, 433-438.

This study investigated the relationships between lactate exchange and removal abilities and the capacity to prolong exercise. Time to exhaustion at a work rate corresponding to VO2max was the dependent variable to reflect the relationship. Blood lactate recovery curves were obtained from untrained Ss (N = 13) after five minutes of exercise at the work rate associated with 90% VO2max.

Time to exhaustion was positively related to lactate exchange and removal abilities and negatively related to the level of lactate at the end of exercise. Lactate exchange was related to capillary density and the number of capillaries per Type I fiber area.

Implication. High lactate exchange and removal abilities facilitate continuing high-intensity aerobic exercise. A high capillary density in slow-twitch fibers (Type I) may explain high lactate exchange ability.

Return to Table of Contents for this issue.