The effects of resistance training on muscle hypertrophy and/or hyperplasia in men

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Exerc Sci > Volume 14(3); 2005 > Article

Exercise Science 2005;14(3): 337-346.

12주간의 저항성 트레이닝이 대퇴근육의 형태학적 변화에 미치는 영향

윤재군, 김창근, 어수주

한국체육대학교

The effects of resistance training on muscle hypertrophy and/or hyperplasia in men

ABSTRACT

Yoon, J.K., Lee, J.K., E, S.J., Kim, C.K. The effects of resistance training on muscle hypertrophy and/or hyperplasia in men. The Korean Society of Exercise Science, 14(3): 337-346, 2005. The purpose of this study was to investigate the effect of weight training(n=5, 12 weeks, 2 day/week; 8 repetitions maximum /set) of adult men(mean age 30.2 years) on muscle fiber hypertrophy and hyperplasia. Computer tomographic scaned on right mid thigh at pre training and post training in order to measurement of mid thigh cross sectional area(CSA), and muscle biopsied on vastus lateralis in order to measurement of muscle fiber composition and CSA. After training, there was an increase in lean body mass(p<.05), but fat mass was a no significantly decrease. No changes occurred in capillary density per fiber area or muscle area. Muscle fiber sections were prepared for histological and histochemical examination. Three fiber types(TypeI, TypeIIa, TypeIIx) were distinguished following routine myofibrillar adenosine triphosphatase histochemistry. Changes by percentage of 3 Muscle fiber types were no significantly compared pre training with post training. Changes by muscle fiber CSA were no significantly but a little increased muscle fiber CSA(5.9%). Competer tomographic scans revealed an increase in the thigh muscle CSA(from 192.80±6.50cm2 to 215.15±5.55cm2, p<.05). Post training, muscle CSA increased in 11.6% than pre training but musle fiber CSA increased in 5.9%. This suggest that adaptations weight training maybe complex and involve muscle fiber hypertrophy and fiber number.

Key words: weight training, hypertrophy, hyperplasia, muscle morphology, cross sectional area(CSA)