Cold Water Immersion after Damaging Exercise Delays the Peak Expression of HSP25 Protein

It is generally believed that unaccustomed exercise causes myofibrillar damage. In recent years، cold water immersion (CWI) following heavy training sessions and matches has been common aiming at reducing soreness. However، there is no strong scientific rationality if this method really accelerates recovery after exercise. In addition، there is a question that if it is possible for this method to interfere in short-term adaptations resulted from exercise. HSP25، as one of the stress proteins that has been shown to play an important role in the remodeling process of recovery after damaging exercise، was discussed in this study. The aim of this study was to investigate the expression of HSP25 protein following cold water immersion after damaging exercise in different recovery time courses. 96 male Wistar rats (weight 290±10 gr and age 8-9 weeks old) were divided into two groups of exercise (Ex) and exercise followed by cold water immersion (Ex+CWI). Each group was divided into 6 subgroups in different time courses before and after the exercise (before، 0. 5، 24، 48، 72، and 168 hours after the exercise). The exercise protocol consisted of 45 minutes of running in a treadmill with incline (speed: 20 m/min. and incline: -17 degrees) and the cold water protocol consisted of 10 minutes of immersion in 10̊ water. The HSP25 protein of skeletal soleus was measured by ELISA method in different time courses. Analysis of variance was used to analyze the data within a group while independent t test was sued to compare the data among the groups in different time courses. The significance level was considered 0. 05. It was observed that the HSP25 protein increased significantly in all time courses except for 168 hours after the exercise (P<0. 05). However، in Ex group، HSP25 level reached its peak level 48 hours after the exercise while the peak time course for Ex+CWI group was 72 hours after the exercise. The most important finding of this study was that CWI delayed the expression of HSP25 protein of skeletal muscle. These findings indirectly indicated that cold water immersion after exercise can increase the response of skeletal muscle to exercise-induced muscle damage and delay the recovery periods.