The effects of multiple daily applications of ice to the hamstrings on biochemical measures, signs, and symptoms associated with exercise-induced muscle damage.

There is inconclusive evidence for the effectiveness of cryotherapy for the treatment of exercised-induced muscle damage (EIMD). Small sample sizes and treatment applications that did not correspond to evidence-based practice are limitations in previous studies that may have contributed to these equivocal findings. The purpose of this study was to examine the effectiveness of daily multiple applications of ice on EIMD throughout the 72-hour recovery period, an icing protocol that more closely resembles current clinical practice. Thirty-three subjects were assigned to either the cryotherapy group (n = 23) or control group (n = 10). The EIMD was induced through repeated isokinetic eccentric contractions of the right hamstring muscle group. The experimental group received ice immediately after induction of EIMD and continued to ice thrice a day for 20 minutes throughout the 72 hours; the control group received no intervention. Isometric torque, hamstring length, pain, and biochemical markers (creatine kinase [CK], alanine aminotransferase, and aspartate aminotransferase [AST]) were assessed at baseline, 24, 48, and 72 hours. Both groups demonstrated a significant change (p < 0.05) in all dependent variables compared with that at baseline, but there was no difference between groups except for pain. The cryotherapy group had significantly (p = 0.048) less pain (3.0 ± 2.1 cm) compared with the control (5.35 ± 2.5 cm) at 48 hours. Although not statistically significant, the cryotherapy group had a greater range of motion and lower CK and AST means at 72 hours compared with that of the control group. Repeated applications of ice can decrease the pain associated with EIMD significantly at 48 hours post EIMD. Although the results may not be unique, the methodology in this study was distinctive in that we used a larger sample size and an icing protocol similar to current recommended treatment practice.