Comparison of strength values and laterality in various muscle contractions between competitive swimmers and untrained persons

摘要

Competitive swimmers may gain a specific train- ing effect as the result of long term exercise in the water. This study aimed to compare isomet-ric, non-isokinetic and isokinetic muscle streng- ths in competitive swimmers and untrained per- sons. Twelve young male adults without exercise experience for over three years and twelve swim- mers with over 10 years of competitive swimming experience performed various strength tests. Non-isokinetic tests were evaluated using one repetition of maximum half squat, vertical jump, and drop jump. Isometric and isokinetic (60 and 180 deg/s) muscle strengths were measured by both legs in knee extension and flexion. There were no significant differences between non- isokinetic and isometric muscle strengths of both groups. On the other hand, all isokinetic parameters in both angular velocities were sig-nificantly larger in competitive swimmers. There was significant laterality of isokinetic strength in untrained persons, but not in competitive swimmers. In addition, right and left differences of isokinetic strength tended to be smaller in competitive swimmers. In conclusion, competi-tive swimmers tended to be superior only in isokinetic strength, which is a similar muscle contraction in the water, and have less right and left differences.