Claytor, RP, MJ Turner, TW Journell, JT Lightfoot. Diminished forearm blood flow response to behavioral challenge in enduranced trained athletes . American College of Sports Medicine, Seattle, WA. Medicine and Science in Sports and Exercise. 25(5) Supplement: S46, 1993.
There is evidence to suggest that individuals who are at risk for cardiovascular disease exhibit an augmented forearm blood flow (FBF) response to psychological stress. The purpose of this study was to determine whether highly-fit, young, normotensive men exhibited altered peripheral vascular responses to a novel behavioral challenge (BC). Ten high-fit (TR) males (VO2max=68.6±1.0 ml(kg¥min)-1) and 17 untrained (UTR) controls (VO2max=50.4±0.8 ml(kg¥min)-1) underwent a computerized modification of the Stroop color-word conflict task and an arithmetic task for monetary reward. Heart rate (HR), mean arterial pressure (MAP), FBF and forearm vascular resistance were measured each minute during the BC. Additionally these variables were assessed during rest conditions prior to BC.
Var REST Mean BC BC min 1 BC min 6
UTR
FBF 2.6±.3 4.3±.4 5.6±.7 4.3±.4
MAP 93.5±3 105.8±3 101.7±3 105.6±3
FVR 42.6±5 32.9±4 24.4±4 30.1±4
TR
FBF 2.6±.1 2.7±.1* 2.8±.2* 2.6±.1*
MAP 88.1±2 99.6±2 96.5±3 100.3±3
FVR 34.9±2 38.1±2* 36.0±2* 40.0±2*
Data are presented as Means±SEM; *p<0.05
These data suggest that eventhough the two groups exhibited similar MAP responses to BC, FBF and FVR responses to BC were altered as a function of endurance fitness. The attenuated FBF and augmented FVR responses to BC may be the result of altered baroreflex functioning during BC.
Supported in part by the American Heart Association (Ohio Affiliate)