The effect of aerobic conditioning on venous pooling in the foot

KENNEY, W. L. and C. GLENN ARMSTRONG. The effect of aerobic conditioning on venous pooling in the foot. Med. Sci. Sports Exerc., Vol. 19, No. 5, pp. 474-479, 1987. Nineteen fit college-age men were studied using foot (mid-arch) mercury-in-silastic strain gauge plethysmography before and after an 8-wk aerobic conditioning (running) program. Foot volume changes were followed through two maneuvers: A 15-s Trendelenburg procedure (passive leg elevation with subsequent relaxation in the dependent position) and a 15-s dynamic dorsi-flexion/plantar flexion exercise and subsequent relaxation. The conditioning regimen consisted of running 40 min, 3 d · wk^-1and resulted in a 10% (P < 0.01) increase in V˙O_2max. Following this regimen, subjects exhibited an increased blood volume drainage during the Trendelenburg procedure (mean ΔV_T= 3.3 ml · 100 ml^-1pre-training, 3.8 ml · 100 ml^-1post-training, P < 0.05), but no significant change in ΔV_E(2.7 ml · 100 ml^-1for all subjects). Muscle pump efficacy, defined as the ratio between ΔV_Eand ΔV_T, did not change (64%). These data suggest that increased aerobic power via weight-bearing exercise training results in an increased foot venous pooling, but does not affect relative muscle pump function. This apparent increase in vascular pooling may be a physical response to the hypervolemia induced by endurance training, aiding in maintaining the constancy of vascular pressures.