During incremental exercise in healthy young individuals, the temporal attainment of peak cardiac output and lowest systemic vascular resistance were positively associated (r = 0.74, p = 0.005).
The temporal attainment of peak cardiac output and lowest systemic vascular resistance during exercise are interdependent and relate inversely to the timing of peak mean arterial pressure.
Effect estimate: r = 0.74
p-value: p=0.005
Abnormal blood pressure (BP) responses to exercise are independently associated with cardiovascular disease. However, the physiological mechanisms underlying exercise BP are unclear, with traditional focus on examining differences in the slope (increase) of BP, or on the absolute maximal BP achieved during incremental exercise. Considering that cardiac function (stroke volume and myocardial deformation) and systemic hemodynamics (e.g, systemic vascular resistance, SVR) are known to reach their peak (i.e. plateau) at submaximal exercise 1 , 2 , different exercise BP progressions could be related to the individually varied attainment of peak hemodynamics. Indeed, young individuals with high BP (at rest) may be categorized into those that have a disproportionately high cardiac output (Q) and those who have a high systemic vascular resistance (SVR) 3 . Identifying the temporal attainment of peak Q and lowest SVR (i.e., their hemodynamic threshold during exercise, “Hem-TRex”) could, therefore, offer new insight to the physiology of exercise BP. Thus, the aim of this exploratory study was to determine individual Hem-TRex of Q and SVR, and their relationship with the Hem-TRex of BP. Based upon the previously suggested phenotypes, it was hypothesized that individuals who reach their peak Q early during incremental exercise would attain their lowest SVR later during incremental exercise, reflecting an inverse association, and that this may relate to exercise BP.
Spahiu et al. (Wed,) conducted a letter in Healthy (n=12). Incremental exercise was evaluated on Association between temporal occurrences of Hem-TRex Q (cardiac output) and Hem-TRex SVR (systemic vascular resistance) (r = 0.74, p=0.005). During incremental exercise in healthy young individuals, the temporal attainment of peak cardiac output and lowest systemic vascular resistance were positively associated (r = 0.74, p = 0.005).