Menstrual cycle effects on cardiovascular drift and maximal oxygen uptake during exercise heat stress

Autor: Jonathan E. Wingo, Ryan L. Earley, Tori Stone, Sarah G. Burnash
Rok vydání: 2020
Předmět:
Zdroj: European Journal of Applied Physiology. 121:561-572
ISSN: 1439-6327
1439-6319
DOI: 10.1007/s00421-020-04542-y
Popis: Compared to other modulators of physiological strain associated with exercise heat stress, hyperthermia results in the greatest magnitude of cardiovascular (CV) drift and associated decrements in maximal oxygen uptake ( $$\dot{V}{\text{O}}_{2\max }$$ ). To determine if elevated core temperature in the luteal phase (LP) of the menstrual cycle results in greater CV drift and reductions in $$\dot{V}{\text{O}}_{2\max }$$ versus the follicular phase (FP). Seven women performed 15- and 45-min cycling bouts on separate occasions (60% $$\dot{V}{\text{O}}_{2\max }$$ , 35 °C) followed by a $$\dot{V}{\text{O}}_{2\max }$$ test during the FP and LP. CV drift was measured between 15 and 45 min during the 45-min bout, and the 15-min bout was for measuring $$\dot{V}{\text{O}}_{2\max }$$ over the same time interval that CV drift occurred. Core temperature during LP was ~ 0.3 °C higher than FP (P 0.05). Heart rate increased significantly over time but was not different between phases (P = 0.78). Stroke volume decreased more over time during LP compared to FP (P = 0.02), but the values were similar at the end of exercise between phases (both time points P > 0.05). $$\dot{V}{\text{O}}_{2\max }$$ decrements for FP (13%) and LP (16%) were also comparable (P = 0.97). The LP–FP difference in core temperature in this study was not sufficient to amplify CV strain and decrements in $$\dot{V}{\text{O}}_{2\max }$$ . Greater differences in core temperature may be required to independently modulate CV drift and accompanying decrements in $$\dot{V}{\text{O}}_{2\max }$$ during prolonged exercise heat stress.
Databáze: OpenAIRE
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