Effects of resistance exercise training on bone mineral density and mechanical strength in growing male rats

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Exerc Sci > Volume 13(1); 2004 > Article

Exercise Science 2004;13(1): 1-14.

저항성 운동이 성장기 흰쥐의 골밀도 및 골강도에 미치는 영향

이상직¹, 이기철¹, 권태동², 김형렬¹

¹위덕대학교
²경북대학교

Effects of resistance exercise training on bone mineral density and mechanical strength in growing male rats

ABSTRACT

Lee, S.J., Kim, H.R., Lee, K.C., Kwon, T.D. Effects of resistance exercise training on bone mineral density and mechanical strength in growing male rats. Exercise Science, 13(1): 1-14, 2004. Effects of resistance exercise training on bone mineral density and mechanical strength in growing male rats. Twenty-one male Sprague-Dawley rats, eight week of age, were assigned randomly to resistance training, sham training, and to a sedentary groups to study the effects of resistance exercise on bone mineral density (BMD) and mechanical strength of the hindlimb bone. A new resistance training apparatus that induces rats to perform motions analogous to human resistance training was designed for this study. Resistance training consisted of squatting at 65～75% of one repetition maximum (1RM) for 45～50 min/day and 3～4 days/week with a progressively increased load. After 12 week of training, the total muscle and the tibia dry weight/body weight were 10% and 24% heavier, respectively, than those of the sedentary rats. Similarly, the tibia bone diameter was 7% greater. A significantly increased femoral neck and midshaft BMD was observed in the resistance tained rats compared with the other groups. The correlation coefficient between maximum breaking force and BMD revealed positive relationships in the femoral neck (r=0.59, p < 0.01) and midshaft (r=0.54, p < 0.02). These results indicate that resistance exercise training enhances the mechanical strength by increasing bone mass of a growing rat.

Key words: weight-lifting training, hindlimb bone, maximum breaking force, DEXA, animal model.