The present study was conducted to examine whether stretching was effective to control muscular atrophy.Subjects were eight male undergraduate students (height 171.4 ± 5.8 cm, body weight 72.2 ± 7.8 kg, and age 20.6 ± 1.1 years) and the muscle analyzed was the vastus lateralis.Firstly, the subjects were instructed to perform strength training for a period of 16 weeks, which was followed by a 12-week detraining period. During the detraining period, either the right or the left leg was stretched daily for 10 minutes (2 sets). The mass of the vastus lateralis muscle was estimated based on its cross-sectional area (CSA), as assessed by magnetic resonance imaging (MRI). Relative decreases in muscle mass were compared between the stretched and the non-stretched control leg.Muscle mass in the non-stretched leg showed significant decreases during detraining, while no significant decreases in muscle mass were detected in the stretched leg. This outcome indicates that stretching can influence muscle plasticity and, therefore, is effective for preventing decreases in muscle mass.In conclusion, this study suggests that, added to its known ability to improve flexibility, accelerate recovery from fatigue, and prevent injuries, static stretching is effective for controlling muscle atrophy.