The Effect of Cuff Width on Muscle Adaptations after Blood Flow Restriction Training.

Unlabelled: Blood flow restriction in combination with low-load resistance training has been shown to increase muscle size and strength; however, the influence of cuff width on these adaptations is unknown.

Purpose: The objective of this study is to determine the influence of different cuff widths on muscle size and strength, and also investigate whether a wider cuff would result in less adaptation compared with a narrow cuff when inflated to the same relative pressure (80% arterial occlusion pressure).

Methods: Eleven physically active males had their arms randomly divided into two separate conditions: low-load blood flow restriction exercise with a narrow cuff (BFR + N, 5 cm) and low-load blood flow restriction exercise with a wide cuff (BFR + W, 10 cm). All participants underwent 12 wk of unilateral elbow flexion at 20% of their one-repetition maximum (1RM). The elbow flexion strength (1RM), elbow flexor muscle cross-sectional area (CSA), arterial blood flow, training volume, RPE, and rating of perceived pain were assessed before and after training.

Results: Elbow flexion 1RM and CSA significantly increased in both conditions (BFR + N = 13.5% and 9% vs BFR + W = 11.9% and 11.2%, respectively). The arterial blood flow was significantly reduced when 80% of the arterial occlusion pressure was applied in both conditions (BFR + N = 61.2% and BFR + W = 63.5%). There were no significant differences in the training volume, RPE, or rating of perceived pain between conditions (P > 0.05).

Conclusion: We wish to suggest that, regardless of cuff width, both protocols produced similar increases in 1RM and elbow flexor muscle CSA, and these responses may be related to the similar training volume and/or similar reductions in arterial blood flow produced when both cuffs were inflated to the same relative pressure.