Effect of increased pressure pain threshold on resistance exercise performance with blood flow restriction

Effect of increased pressure pain threshold on resistance exercise performance with blood flow restriction. J Strength Cond Res 37(6): 1204–1210, 2023—This study aimed to examine whether increasing pressure pain threshold (PPT) through isometric handgrip exercise (HG) affects the number of repetitions completed and discomfort with knee extension exercise (KE) with blood flow restriction (BFR), and examine whether performing additional exercise leads to a further increase in PPT. Forty-one participants completed 2 trials: rest followed by low-load KE with BFR at 80% of resting arterial occlusion pressure (Rest + KE BFR) and low-intensity (30% of maximal strength) HG exercise followed by KE with BFR (HG + KE BFR). Pressure pain threshold was measured before and after exercise at the forearm and tibialis anterior. Results are presented as median difference (95% credible interval). Pressure pain threshold increased at the forearm (Bayes factor [BF10]: 5.2 × 107) and tibialis anterior (BF10: 1.5 × 106) after HG exercise. However, this did not lead to greater repetitions being completed with BFR exercise (0.2 [−0.1, 0.6] repetitions, BF10: 0.07). Pressure pain threshold after BFR exercise was not augmented over that observed with HG exercise (0.02 [−0.15, 0.2] kg·cm−2, BF10: 0.175) at the forearm. More data are needed in the lower body to determine which model best fits the data (BF10: 0.84). Discomfort with BFR exercise was not different between conditions (1.0 [−2.3, 4.4] arbitrary units, BF10: 0.10). The pain-reducing effect of prior exercise did not change the repetitions completed with BFR exercise, suggesting that the change in PPT may not have been great enough to alter performance. Performing additional exercise did not elicit further increases in PPT nor was perceived discomfort to BFR exercise altered by changes in PPT.