Journal
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
Volume 324, Issue 4, Pages R568-R573Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpregu.00314.2022
Keywords
aquatic exercise; flow-mediated dilation; shear stress; water immersion
Categories
Ask authors/readers for more resources
This study investigated the effects of exercise in 32 °C and 38 °C water on flow-mediated dilation (FMD). The results showed that exercise in water can decrease brachial artery shear and FMD compared to land-based exercise, and exercise in 38 °C water can increase brachial shear and FMD.
Flow-mediated dilation (FMD) provides a valid bioassay of vascular function in humans. Although water immersion induces hemodynamic effects that modify brachial artery shear stress, it is unclear whether water-based exercise modifies FMD. We hypothesized that exercise in 32 & DEG;C water would decrease brachial artery shear and FMD relative to land-based exercise, whereas exercise in 38 & DEG;C would increase brachial shear and FMD. Ten healthy participants (8 males; 23.9 & PLUSMN; 3.3 yr) completed 30 min of resistance-matched cycle exercise in three separate conditions: on land and in 32 & DEG;C and 38 & DEG;C water. Brachial artery shear rate area under the curve (SRAUC) was measured throughout each condition, with FMD measured pre- and postexercise. Brachial SRAUC increased during exercise in all conditions and was highest across the 38 & DEG;C condition compared with Land and 32 & DEG;C conditions (38 & DEG;C: 27,507 & PLUSMN; 8,350 vs. Land: 9,908 & PLUSMN; 4,738 vs. 32 & DEG;C: 13,840 & PLUSMN; 5,861 1/s, P < 0.001). Retrograde diastolic shear was greater during 32 & DEG;C than both Land and 38 & DEG;C conditions (32 & DEG;C:-3,869 & PLUSMN; 2,198 vs. Land:-1,602 & PLUSMN; 1,334 vs. 32 & DEG;C:-1,036 & PLUSMN; 1,754, P < 0.01). FMD increased as a result of 38 & DEG;C (6.2 & PLUSMN; 1.9 vs. 8.5 & PLUSMN; 2.7%, P = 0.03), with no change in the Land exercise (6.3 & PLUSMN; 2.4 vs. 7.7 & PLUSMN; 2.4%, P = 0.10) or 32 & DEG;C condition (6.4 & PLUSMN; 3.2 vs. 6.7 & PLUSMN; 3.2%, P = 0.99). Our findings indicate that cycle exercise in hot water attenuates retrograde shear, increases antegrade shear, and FMD. Exercise in 32 & DEG;C water induces central hemodynamic changes relative to land-based exercise, but these do not translate to increases in FMD in either condition, likely due to the impact of increased retrograde shear. Our findings indicate that modification of shear has direct acute impacts on endothelial function in humans.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available