Skeletal Muscle''s Quantitative Isotonic and Isometric Resistance Exercises

• Main Author: 洪慈穗
• Other Authors: 蔚順華
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/54256775670460547841

碩士 === 國立體育學院 === 運動科學研究所 === 85 === 　　The purpose of this study was to determine the relationship between percentage of one repetition maximun (%IRM) and repeptions of isotonic concentric exercise, and the relationship between percentage of maximum voluntary contraction (%MVC) and sustained time of isometric exereise in normal men and women aged 20~30 yeas. Twenty male and 20 female non-athletic students were measured using their dominant knee extensors. Isometric sustained times were measured at different %MVC(40, 50, 60, 70, 80, 90, 100%MVC) with the knee flexed at 60°. One week later, the numbers of repeptions of 0-90° isotonic concentric exercise at different %RM (40, 50, 60, 70, 80, 90, 100%IRM) were measured. Each Load measurement was separated by one day. Cybex Leg Extensor machine, equipped with a custom-made load-descending attenuator, was used in the study. The isotonic regression equation (40-100%RM) for the male was Rep=101.89-195.38L+95.67L2 (L indicates %RM and REM indicatesrepetitions, the restriction is that L equals to one, i.e., Rep will be set to one at 100%RM) , with coefficient of determination R2 equal to .7771. For the female, Rep=134.57-274284L+142.88L2 (40-96%RM), with R2 equal to .7895. In isometic exercise, Time=150.04-192.53L+45.54L2 for males (Time in seconds, L indicated %MVC), and Time=207-322.42L+118.09L2 for females, with R2equal to .8394 respectivaly. In both types of exercisa, the absolute strength (Kg) of male students were significantly (p<.05) greater than that of females. After normalization for body weigh, the differences in relative strength decreased but still significant (p<.05). There was no significant difference between males and female in the number of repeptions at various %RM. The females'' 50 and 40%MVC isometric sustained times were significamtly (p<.05) greater than that of the males. Using the above regression equations, the loads and their effective repetitions, or their sustained times can be more precisely determined to obtain optimal training effects for muscle strength, power, and endurance.