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Blood Pressure Responses to Postexercise Circulatory Occlusion Are Attenuated After Exercise-Induced Muscle Weakness.

Authors :
Lee JB
Katerberg C
Bommarito JC
Power GA
Millar PJ
Source :
Medicine and science in sports and exercise [Med Sci Sports Exerc] 2023 Sep 01; Vol. 55 (9), pp. 1660-1671. Date of Electronic Publication: 2023 Apr 05.
Publication Year :
2023

Abstract

Purpose: Exercise blood pressure (BP) responses are thought to be determined by relative exercise intensity (percent maximal voluntary contraction (MVC) strength). However, cross-sectional studies report that during a static contraction, higher absolute force is associated with greater BP responses to relative intensity exercise and subsequent muscle metaboreflex activation with postexercise circulatory occlusion (PECO). We hypothesized that a bout of unaccustomed eccentric exercise would reduce knee extensor MVC and subsequently attenuate BP responses to PECO.<br />Methods: Continuous BP, heart rate, muscle oxygenation, and knee extensor electromyography were recorded in 21 young healthy individuals (female, n = 10) during 2 min of 20% MVC static knee extension exercise and 2 min of PECO, performed before and 24 h after 300 maximal knee extensor eccentric contractions to cause exercise-induced muscle weakness. As a control, 14 participants repeated the eccentric exercise 4 wks later to test whether BP responses were altered when exercise-induced muscle weakness was attenuated via the protective effects of the repeated bout effect.<br />Results: Eccentric exercise reduced MVC in all participants (144 ± 43 vs 110 ± 34 N·m, P < 0.0001). BP responses to matched relative intensity static exercise (lower absolute force) were unchanged after eccentric exercise ( P > 0.99) but were attenuated during PECO (systolic BP: 18 ± 10 vs 12 ± 9 mm Hg, P = 0.02). Exercise-induced muscle weakness modulated the deoxygenated hemoglobin response to static exercise (64% ± 22% vs 46% ± 22%, P = 0.04). When repeated after 4 wks, exercise-induced weakness after eccentric exercise was attenuated (-21.6% ± 14.3% vs -9.3 ± 9.7, P = 0.0002) and BP responses to PECO were not different from control values (all, P > 0.96).<br />Conclusions: BP responses to muscle metaboreflex activation, but not exercise, are attenuated by exercise-induced muscle weakness, indicating a contribution of absolute exercise intensity on muscle metaboreflex activation.<br /> (Copyright © 2023 by the American College of Sports Medicine.)

Details

Language :
English
ISSN :
1530-0315
Volume :
55
Issue :
9
Database :
MEDLINE
Journal :
Medicine and science in sports and exercise
Publication Type :
Academic Journal
Accession number :
37017549
Full Text :
https://doi.org/10.1249/MSS.0000000000003182