Effects of physical training and mental practice of in-clothes swimming: assessment by physiological parameters

PURPOSE: This study examined whether a short-term physical or mental training reduces the physiological load and perceived exertion of the in-clothes swimming. METHODS: The study included 24 male inter-collegiate competitive swimmers with no previous experience of the in-clothes swimming. Prior to the training, the subjects performed 200-meter swimming with two styles of swimming, namely the crawl and elementary backstroke, and the degree of perceived exertion in the Borg scale, heart rate, and blood lactic acid level were determined. Following this baseline determination, the subjects were divided into 4 groups with 6 individuals each. These four groups were Group A "in-clothes training", Group B "image training", Group C "swimsuit training", and Group N "no training". Group A and C were lectured on the in-clothes swimming and practiced 7.5 min-long in-clothes swimming per day for a week with the two swimming styles, with Group A subjects wearing daily clothes and Group C subjects in swimsuits. Group B received 15 min of nonphysical mental practice primarily through viewing video recording of swimming performance everyday for a week. No training was given to Group N. At the completion of the training session, the subjects underwent the 2nd 200-meter swimming, and the physiological parameters were determined. RESULTS: The 1st in-clothes swimming load test showed that the elementary backstroke swimming resulted in significantly lower values of heart rate, blood lactic acid level, and perceived exertion than the crawl. For Group N, no difference was observed in the physiological parameters between the 1st and 2nd load test with either the elementary backstroke or crawl. Upon the 2nd in-clothes load test with the elementary backstroke, all three parameters were lower for Group A, B, and C than those seen for the 1st load test, and these differences were statistically significant, except for blood lactic acid in Group A. The 2nd in-clothes load test with the crawl showed that both heart rate and blood lactic acid were lower than those of the 1st load test for all three groups, with the differences in heart rate and blood lactic acid in Group A and that in blood lactic acid in Group B reaching the statistic significance. With respect to perceived exertion, the Borg score determined after the in-clothes load test with the crawl was significantly reduced for Group A, B, and C. The score after the in-clothes load test with the elementary backstroke was significantly reduced only for Group A. CONCLUSION: The elementary backstroke, when practiced in-clothes, imposes a relatively less physiological load. The present training methods can reduce physiological load and/or perceived exertion of the in-clothes swimming. Thus, both image training and swimsuit swimming are equally effective as a training method of the in-clothes swimming.