Perceived Discomfort is Decreased After Repeated Bouts of Isometric Handgrip Exercise With and Without Blood Flow Restriction

Abstract

Blood flow restricted exercise appears to be more discomforting than the same exercise without blood flow restriction. Changes in discomfort have not been investigated following repeated bouts of isometric exercise. It is possible that the isometric contractions may further trap metabolites resulting in greater discomfort. The purpose was to investigate the effects of six weeks of isometric handgrip exercise on perceived discomfort and willingness to continue with that form of exercise. 135 participants trained three times a week for six-weeks. The training consisted of four sets of 2-min low-intensity contractions (at 30% of their maximal voluntary contraction) with blood flow restriction (LI + BFR) and without blood flow restriction (LI). The maximal contraction group performed four, five second maximal contractions (MAX). Discomfort was measured post-exercise on the first, ninth, and last training session using the CR10+ scale. Changes in discomfort from the 1^st to the 18^th session were greater in the LI [-1.7 (1.7) AU] (BF₁₀ = 6952.769) and LI + BFR [-1.5 (1.9) AU] (BF₁₀ = 404.996) when compared to MAX group [0.04 (1.5) AU]. There was no difference between LI and LI + BFR (BF₁₀ = 0.241). Although there were differences in discomfort, there was no difference in the desire to continue the same exercise amongst groups (BF₁₀ = 0.208). Discomfort decreased more in both low intensity groups compared to the MAX group. Despite greater decreases in discomfort there was no difference in willingness to continue with the same form of exercise. This suggests other factors besides discomfort may influence an individual’s willingness to continue with the same type of exercise.