Whole-body Sweating Rate And Percentage Of Weight Lost By Dehydration In Two Different Volleyball Trainings

Abstract

PURPOSE: To compare the whole-body sweating rate and percentage of weight lost by dehydration in two different types of indoor training in male college volleyball players. METHODS: 8 male college volleyball players were evaluated from February to March 2017. We calculated the whole-body sweating rate and the percentage of weight lost by dehydration in two different training session [Volleyball training (VO) and Volleyball training plus resistance training (VR)]. To evaluate the whole-body sweating rate, body and sport bottle were weighted before and after training to calculate changes in body mass and fluid intake (subjects were allowed to drink ad libitum during trainings). Subjects had to wear minimal clothing, to dry their skin with towels and to void their bladders before being weighed. Active time of each training was evaluated employing a stopwatch. Results are shown in median, minimum and maximum. RESULTS: The active time for VO were 117 min (72 - 135); on the other hand, for VR were 107 min (97 - 126) (p= 0.96). A higher whole-body sweating rate was found from VO (11.8 ml/min, 5.7 - 13.3) than VR (10.1 ml/min, 7.0 - 12.3) but were not significantly different (p= 0.42). Conversely, a lower percentage of weight lost by dehydration was found from VO (0.7, 0.3 - 1.4 %) than VR (0.8, 0.2 - 1.3 %), but again were not significantly different (p=0.69). CONCLUSIONS: In this study we found the sweating rate and body weight loss by dehydration were similar despite the training sessions were different. Maybe this happened because the active time was the same. However, it is known that intensity also plays a role in sweating rate, but it wasn’t measured here, and therefore, the differences in training intensity may soft the differences in sweating rate and body weight loss despite there were the same active time.