Exercise-induced hypoalgesia following blood flow restricted exercise

Objectives: Assess the repeatability of exercise-induced hypoalgesia (EIH) following low-load resistance exercise with blood flow restriction (LL + BFR) and the magnitude of EIH following LL + BFR, high-load resistance exercise, and a control intervention 1-h after exercise. Design: Crossover design. Setting: University laboratory. Participants: 15 females, 15 males. Main outcome measures: Pain pressure threshold and tolerance of the rectus femoris, gastrocnemius, and biceps brachii pre-exercise and 0-, 15-, 30-, 45-, and 60-min post-exercise. Results: There was no significant (p = 0.211-0.741) difference in pain pressure threshold or tolerance between LL + BFR1 and LL + BFR2 suggesting that EIH following LL + BFR is repeatable. LL + BFR elicited a significant (p = 0.001-0.043) increase in local pain pressure threshold (1.57 + 1.21-0.98 + 1.48 Delta kgf) and tolerance (1.98 + 2.65-0.83 + 2.15 Delta kgf) up to 1-h post-exercise. High-load resistance exercise elicited a significant (p = 0.003-0.034) increase in pain pressure threshold 0-min post-exercise (1.69 + 1.74 Delta kgf) and tolerance 0- and 15-min post-exercise (2.31 + 2.44 Delta kgf; 0.56 + 1.83 Delta kgf, respectively) then returned to pre-exercise levels. LL + BFR elicited a significant (p = 0.025-0.046) increase in systemic pain pressure tolerance (0.77 + 0.88 Delta kgf) of the gastrocnemius as well as pain pressure threshold (0.53 + 0.54 Delta kgf) and tolerance (0.49 + 1.02 Delta kgf) of the biceps brachii, when collapsed across Time. Conclusions: LL + BFR may be a repeatable, effective pain management intervention that can produce prolonged EIH.