Frequent low‐load ischemic resistance exercise to failure enhances muscle oxygen delivery and endurance capacity

Abstract

This study investigated the effects of frequent low-load ischemic resistance exercise performed to failure on quadriceps size and performance, muscle activation, oxygen kinetics and cardiovascular responses. Ten healthy males performed knee-extension exercise for 4 weeks (4 sessions/week) at 15% maximal voluntary muscle contraction (MVC). One leg was trained with free blood flow (C-leg) while in the other leg (I-leg) ischemia was induced by an inflatable cuff (≥230 mmHg). Quadriceps cross-sectional area (CSA) of the I-leg increased by 3.4% (P<0.05). A tendency for smaller increase in muscle CSAs at the cuff level was observed. MVC force did not change in either leg, whereas the number of repetitions during exercise test to failure increased (P<0.01) by 63% in I-leg and 36% in C-leg. The decrease in muscle oxygenated hemoglobin concentration acquired by NIRS was attenuated (P<0.01) by 56% in I-leg and 21% in C-leg. Electromyographic amplitude of rectus femoris in I-leg was ∼45% lower (P<0.025) during the ischemic test. Also, ∼9% increase (P<0.05) in pre-exercise diastolic pressure was observed. In conclusion, substantial gains in muscle endurance capacity were induced, which were associated with enhanced muscle oxygen delivery. The potential negative effects of ischemic exercise with high cuff pressure on muscle and nerve and on arterial pressure regulation need further investigation.

Exercise with Blood Flow Restriction: An Updated Evidence-Based Approach for Enhanced Muscular Development

“…This may adversely affect exercise performance and negatively impact training adaptation. Furthermore, it is conceivable that the muscular hypertrophy stimulus may be attenuated directly below the cuff [42], though further research on this point is needed.…”

Exercise and Blood Flow Restriction

“…It was determined that occluded and unoccluded localized muscular endurance increased but to a greater extent for the I--Leg 63 and 27% vs. the C--Leg 36 and 11%, respectively. These studies (38,90) suggest that the addition of BFR during resistance training can promote superior increases in localized muscular endurance and might promote a crosseducation effect on contralateral muscle groups not trained via BFR.…”

Potential exercise countermeasures to attenuate skeletal muscle deterioration in space

“…Furthermore, these benefits have also been observed with low intensity (~20-30% concentric 1RM) resistance training combined with BFR. 25,35,36 Interestingly, recent findings from Yasuda et al 25 indicate that these benefits may not be exclusive to the BFR limbs. For example, restricting the upper arm during chest press resulted in significant muscle hypertrophy and strength gains in the pectoralis.…”