Effects of hydrotherapy on muscle damage and recovery profile after eccentric exercise in arm

PURPOSE: This study aimed to examine the effect of hydrotherapy at different temperatures following eccentric exercise on muscle damage and recovery profiles in young men. METHODS: Male college students without any cardiovascular or orthopedic disorders were randomly assigned to three hydrotherapy groups: a 5°C group (cold water, COLD), a 15°C group (cool water, COOL), and a control group (CON).Thirty maximal eccentric exercises were performed using the participants’ nondominant elbow flexor muscles. Each treatment consisted of immersion five times for 1 minute, along with a 1-minute rest between each immersion trial. Each intervention was conducted immediately after the eccentric exercise and every 24 hours. Changes in the level of exercise-induced muscle damage (EIMD), circumference, muscle soreness, range of motion (ROM), maximum voluntary isometric contraction (MVIC), muscle dynamic stiffness, and muscular echo intensity (EI) were measured.All parameters were measured at 24, 48, 72, and 96 hours after exercise, as well as immediately before and after exercise. RESULTS: Muscle soreness was significantly higher in the COLD group than in the other groups. Moreover, the muscle circumference tended to increase in the COLD group than in the other groups. However, an increase in the dynamic stiffness and EI, promoting the recovery of MVIC, was observed in the COOL group. In addition, ROM tended to return more rapidly in the COOL group than in the other groups. CONCLUSIONS: This study suggests that hydrotherapy at moderately low temperatures compared with that at extremely low temperatures may induce relatively positive effects on EIMD and recovery phases following eccentric exercise in the arms.