The Effect Of Long-term Exercise Adherence After Lumbar Exercise Rehabilitation For Low Back Disorders

Abstract

METHODS: Forty female mice(4 weeks old) were randomly divided into a lifelong exercise(LE), premenopausal exercise(PE), adolescent exercise(AE) and blank control(BC) groups consisting 10 mice in each group. The mice in the LE firstly underwent swimming exercise for 12 consecutive weeks during the 5 weeks to 13 months age period, for 60 min, with the intensity of 3% of the body weight, 5 times a week; and then performed treadmill exercise until two weeks before the slaughter, for 60 min ,with the speed of 10 m/s, 4 times a week. The mice in the PE underwent treadmill exercise for 8 weeks during 30-38 weeks age period, for 60 min ,with the speed of 10 m/s, 4 times a week. The mice in the AE underwent swimming exercise for 8 weeks during 5 to 13 weeks age period , for 60 min, with the intensity of 3% of the body weight, 5 times a week. The mice in the BC underwent no exercise for the entire experiment. All animals were sacrificed by intravenous bloodletting after 11 months of feeding. Dual-energy x-ray absorptiometry was used to estimate the Bone Mineral Density(BMD), Bone Mineral Content(BMC) and body composition. RESULTS: A total of 37 mice completed the study.(1) The growth rate of BMD in the AE group(0.140±0.117g/cm2/d,P<0.05) was higher than in the other groups during 13-19 weeks age period. (2) Compared with the BC group, the BMD of AE group (0.077±0.019 g/cm2, P=0.011) and LE group (0.065±0.026 g/cm 2 , P =0.011) significantly increased; the muscle mass of LE group (18.222±4.631g, P=0.003), PE group (16.500±5.798g, P=0.010) and AE group (14.700±7.917g, P =0.042) significantly increased; the fat mass and body fat rate of PE group (1.500±4.478g, P=0.003; -22.4±11.3%, P=0.00) and LE group (1.556±3.9721g, P=0.003; -23.5±7.0%, P=0.000) significantly decreased. CONCLUSIONS: The present study demonstrates that:(1)adolescent physical activity can help mice to accumulate peak bone mass;(2) both lifelong exercise and starting exercise at an old age can help prevent fat accumulation and muscle mass reduction.