Abstract
Few studies compare acute muscle swelling between upper and lower limbs with blood flow restriction (BFR), and lower pressures may reduce the often-reported discomfort. The purpose was to examine differences in acute muscle swelling, discomfort, and exercise preference between low-load BFR and high-load resistance exercise in upper and lower limbs. Sixty-one participants (25.7 ± 7.9 years; 32 males, 29 females) completed four exercise conditions: upper limbs (UL) randomized to low-load BFR (BFR-UL) or high load (HL-UL), then lower limbs (LL) randomized to low-load BFR (BFR-LL) or HL (HL-LL). BFR-LL was performed at 30% 1RM with four sets to failure at 50 mmHg cuff pressure; HL exercises were at 70% 1RM with four sets of 8-12 reps. Swelling, discomfort (0-10 scale), and exercise preference were assessed. Results were presented as mean [SD]. The most probable predictor of swelling was identified in limbs (posterior inclusion probability = 0.996; BF10 = 846.447; BFincl = 156.329), with strong evidence against a condition × limb interaction for swelling (BFincl = 0.178). Swelling had a greater increase in lower limbs compared with the upper limbs (BF10 = 946.447; BFincl = 158.344), while evidence for condition effects was anecdotal (BFincl = 0.206). There was strong evidence against a set × limb × condition interaction for discomfort (BF10 = 0.083), with no preference for upper limb condition (BF10: 0.236), and anecdotal preferences for the lower limbs (BF10 = 0.626). Acute muscle swelling and discomfort did not differ across conditions, supporting low-load, low-pressure BFR as a practical alternative to high-load training.