The effect of water temperature and salinity on recovery from exercise induced muscle damage

Abstract

Water immersion strategies are commonly employed to reduce symptoms of exercise induced muscle damage (EIMD). However, little research has established whether recovery is stimulated via effects of hydrostatic pressure or water temperature (Leeder et al., 2012).This study investigated the effects of four immersion protocols of differing temperature and hydrostatic pressures (control (CON), cold water immersion (CWI), thermo-neutral water immersion (TWI) and thermo-neutral saline immersion (TSI) on recovery from EIMD. Twenty-five recreationally active males participated in the study. Participants completed 5 X 8 min of downhill running (-10%, 60% max treadmill velocity) separated by 2 min rest to induce EIMD. Within 30 min post exercise participants were randomly assigned to either: CWI (15 min, 10-15°C), TWI (15 min, ~35°C), TSI (15 min, ~35°C, 30% salinity) or a CON (15 min seated rest). Anthropometric measures, circumference of left (LL) and right leg (RL), cross sectional area (CSA) of rectus femoris via ultra sound scans of LL and RL, countermovement jumps (CMJ), assessment of maximal voluntary contractions (MVC), pain scales, recovery scales, creatine kinase (CK) and blood lactate were obtained across 6 time points (familiarisation up to 72 h post EIMD). Muscle damaging exercise resulted in a significant reduction of CMJ in CON from pre-trials to 24 h post (-10.0 ± 6.7%, p = 0.001), and a significant increase for RL (1.1 ± 0.7%, p = 0.02) and LL (1.1 ± 0.6%, p = 0.03) circumference from pre trials to 24 h post. CK increased significantly for CON and TSI groups between pre-trials and 24 h post (121.3 ± 28.5%, p = 0.001 ; 130.3 ± 95.0%, p < 0.001) respectively, however TSI group demonstrated a significant reduction between 24 h and 48 h post (p = 0.001). No significant interaction effect was present between groups across measures of LL and RL circumference, CK, MVIC, CMJ and pain scales (P > 0.05). Although the early indications from percentage change in performance may reflect a greater effect of a CWI protocol over TSI, the lack of statistical significance across variables provides little indication to whether recovery is stimulated primarily via temperature of the water or hydrostatic pressure. Further, investigations into the effect of a TSI protocol on recovery on a larger sample size, and the effects of TSI on training adaptation should be considered to evaluate the effectiveness of TSI as a recovery strategy.