1. Training at non-damaging intensities facilitates recovery from muscle atrophy.
- Author
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Itoh Y, Murakami T, Mori T, Agata N, Kimura N, Inoue-Miyazu M, Hayakawa K, Hirano T, Sokabe M, and Kawakami K
- Subjects
- Analysis of Variance, Electric Stimulation, Female, Hindlimb Suspension, Histocompatibility Antigens Class I metabolism, Humans, Isometric Contraction, Male, Muscular Atrophy physiopathology, MyoD Protein metabolism, Myogenin metabolism, PAX7 Transcription Factor metabolism, Muscle, Skeletal physiology, Muscular Atrophy rehabilitation, Recovery of Function physiology, Resistance Training methods
- Abstract
Introduction: Resistance training promotes recovery from muscle atrophy, but optimum training programs have not been established. We aimed to determine the optimum training intensity for muscle atrophy., Methods: Mice recovering from atrophied muscles after 2 weeks of tail suspension underwent repeated isometric training with varying joint torques 50 times per day., Results: Muscle recovery assessed by maximal isometric contraction and myofiber cross-sectional areas (CSAs) were facilitated at 40% and 60% maximum contraction strength (MC), but at not at 10% and 90% MC. At 60% and 90% MC, damaged and contained smaller diameter fibers were observed. Activation of myogenic satellite cells and a marked increase in myonuclei were observed at 40%, 60%, and 90% MC., Conclusions: The increases in myofiber CSAs were likely caused by increased myonuclei formed through fusion of resistance-induced myofibers with myogenic satellite cells. These data indicate that resistance training without muscle damage facilitates efficient recovery from atrophy. Muscle Nerve 55: 243-253, 2017., (© 2016 Wiley Periodicals, Inc.)
- Published
- 2017
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