BLOOD-PRESSURE, HEMODYNAMIC, AND THERMAL RESPONSES AFTER CYCLING EXERCISE

Seated recovery [at 5, 15, 20, 40, and 60 min (R5,15,20,40,60) body temperature (T) and blood pressure were examined after 45 min of cycling exercise (54 +/- 5% maximal O2 uptake) in 12 normotensive males to study the relationship between postexercise thermal and hemodynamic responses. Data were analyzed with a repeated-measures analysis of variance. Systolic (SBP, R15,20,40; P < 0.01) and mean arterial (MAP, R15,20; P < 0.05) blood pressures were significantly lower, but diastolic blood pressure (DBP) was unchanged. Heart rate (R5,15,20, P < 0.001) was above that measured at rest. Decreases in mean skin T (T(sk)BAR, R15,20,60; P < 0.01) and increases in core T (T(c), R5,15,20; P < 0.01) were found. Significant negative correlations averaging -0.68 (R15,20,40) and -0.69 (R15,20,40) were demonstrated for T(sk)BAR and SBP and MAP, respectively. Increases in thigh T(sk) (R5,15,20; P < 0.00001) and decreases in calf (R15,20,40,60; P < 0.00001) and chest (T(chest), R5,15,20,40; P < 0.00001) T(sk) were found. Significant negative correlations averaging -0.67 (R5,15,20,40) and -0.71 (R20,40,60) were demonstrated for T(chest) and SBP and MAP, respectively. Inverse relationships between various regional Ts and blood pressure and the increased R T(c) suggest a vasodilatory response in the visceral organs and/or lower hm leading to a pooling of blood and transient decreases in blood pressure by a reduced venous return, although not affecting stroke volume and cardiac output.