Perceptual and arterial occlusion responses to very low load blood flow restricted exercise performed to volitional failure

PURPOSE: Studies examining perceptual and arterial occlusion responses between blood flow restricted exercise and high load exercise often prescribe an arbitrary number of repetitions, making it difficult for direct comparisons. Therefore, the purpose of this study was to compare these protocols when performed to volitional failure.

METHODS: Individuals completed four exercise conditions varying in load and pressure: (i) 15% 1RM; no restrictive pressure, (ii) 15% 1RM; 40% arterial occlusion pressure, (iii) 15% 1RM; 80% arterial occlusion pressure, and (iv) 70% 1RM; no pressure. Four sets of knee extension exercises were performed until volitional failure (or until 90 repetitions per set) was completed.

RESULTS: A total of 23 individuals completed the study. While all conditions increased arterial occlusion pressure, the greatest increases (~30%) were observed in the blood flow restriction conditions. All lower load conditions resulted in greater RPE and discomfort than that of the high load condition, but only discomfort was increased further when adding blood flow restriction.

CONCLUSION: High load exercise will likely be perceived more favourably than lower load exercise to volitional failure; however, those who are incapable or unwilling to lift heavier loads may use blood flow restriction to help reduce the volume needed to reach volitional failure, although this will likely increase discomfort.