The effect of acute and repeated ischemic preconditioning on recovery following exercise-induced muscle damage

Objectives: The aim of this investigation was to determine if acute or repeated applications of ischemic preconditioning (IPC) could enhance the recovery process, following exercise induced muscle damage (EIMD). Design: Randomized control trial. Methods: Twenty-three healthy males were familiarised with the muscle damaging protocol (five sets of 20 drop jumps from a 0.6 m box) and randomly allocated to one of three groups: SHAM (3 & times; 5 min at 20 mmHg), Acute IPC (3 & times; 5 min at 220 mmHg) and Repeated IPC (3 days x 3 & times; 5 min at 220 mmHg). The indices of muscle damage measured included creatine kinase concentration ([CK]), thigh swelling, delayed onset muscle soreness, counter movement jumps (CMJ) and maximal voluntary isometric contraction (MVIC). Results: Both acute and repeated IPC improved recovery in MVIC versus SHAM. Repeated IPC led to a faster MVIC recovery at 48 h (101.5%) relative to acute IPC (92.6%) and SHAM (84.4%) (P < 0.05). Less swelling was found for both acute and repeated IPC vs. SHAM (P < 0.05) but no group effects were found for CMJ, soreness or [CK] responses (P > 0.05). Conclusion: Taken together, repeated IPC can enhance recovery time of MVIC more than an acute application, and both reduce swelling following EIMD, relative to a SHAM condition. (c) 2021 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.