title: Brachial artery modifications to blood flow-restricted handgrip training and detraining.
abstract: Low load resistance training with blood flow restriction (BFR) can increase muscle size and strength, but the implications on the conduit artery are uncertain. We examined the effects of low-load dynamic handgrip training with and without BFR, and detraining, on measures of brachial artery function and structure. Nine male participants (26 ± 4 yr, 178 ± 3 cm, 78 ± 10 kg) completed 4 wk (3 days/wk) of dynamic handgrip training at 40% 1 repetition maximum (1RM). In a counterbalanced manner, one forearm trained under BFR (occlusion cuff at 80 mmHg) and the other under nonrestricted (CON) conditions. Brachial artery function [flow-mediated dilation (FMD)] and structure (diameter) were assessed using Doppler ultrasound. Measurements were made before training (pretraining), after training (posttraining), and after 2-wk no training (detraining). Brachial artery diameter at rest, in response to 5-min ischemia (peak diameter), and ischemic exercise (maximal diameter) increased by 3.0%, 2.4%, and 3.1%, respectively, after BFR training but not after CON. FMD did not change at any time point in either arm. Vascular measures in the BFR arm returned to baseline after 2 wk detraining with no change after CON. The data demonstrate that dynamic low-load handgrip training with BFR induced transient adaptations to conduit artery structure but not function.
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
authors.forename: Julie E A
authors.initials: JE
authors.lastname: Hunt
authors.forename: Lucy A
authors.initials: LA
authors.lastname: Walton
authors.forename: Richard A
authors.initials: RA
authors.lastname: Ferguson
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001132:Arm / Q000098:blood supply / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D001916:Brachial Artery / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005542:Forearm / Q000098:blood supply / Q000502:physiology*; D006225:Hand / Q000098:blood supply*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology*; D055070:Resistance Training / Q000379:methods; D014664:Vasodilation / Q000502:physiology