Acute flywheel exercise does not impair the brachial artery vasodilation in healthy men of varying aerobic fitness.

Abstract

The cardiovascular response to variable load exercise on a flywheel ergometer is still unknown. This study examined the effects of flywheel exercise on cardiovascular response and brachial artery vasodilation capacity in healthy, active men. In this cross-sectional study, nineteen men (20-57 years old) completed three laboratory visits, including a ramp exercise test to determine their maximal oxygen uptake JOURNAL/blpmo/04.03/00126097-202106000-00008/inline-graphic1/v/2021-04-27T091817Z/r/image-tiff max, and exercise intervention on a flywheel ergometer set at 0.075 kg·m2 moment of inertia. After the ramp test cessation, all participants were allocated into aerobically untrained (n = 10) and trained (n = 9) groups. Throughout the flywheel exercise, cardiovascular demands were continuously monitored via Finapres, while a pre/postflow-mediated dilation (FMD) assessment was performed using ultrasound imaging. There were no differences observed between the groups in their anthropometrics, age or resting brachial artery diameter, while the JOURNAL/blpmo/04.03/00126097-202106000-00008/inline-graphic2/v/2021-04-27T091817Z/r/image-tiff max was ~15% higher (P = 0.001) in trained compared to aerobically untrained group. The cardiovascular response to the flywheel exercise was similar between the groups, with peak mean arterial pressure and heart rate readings reaching ~160 mmHg and ~140 bpm, respectively. The flywheel exercise did not impair the FMD (%) response, which was comparable between the groups (P = 0.256). When these data were pooled, the regression analysis showed an inverse relationship among FMD (%), age (β = -0.936, P = 0.001) and JOURNAL/blpmo/04.03/00126097-202106000-00008/inline-graphic3/v/2021-04-27T091817Z/r/image-tiffmax. (β = -0.359, P = 0.045). Although aerobic fitness alone does not directly explain the FMD response to flywheel exercise, aerobically untrained individuals, as they get older, tend to have lower brachial artery FMD.