Physiological adaptations to physical training. In Training for sport and activity, Chapter 11. However, at some point a reduction in training or complete inactivity will produce a deterioration in performance. Loss of Muscle Strength and Power Skeletal muscles undergo a considerable decrease in size with inactivity, and are accompanied by a loss in strength and power. Reduced activity over a long period of time can cause small diminutions to accumulate so that eventually they will become substantial.
Reductions are relatively small during the first few months following cessation of training.
Similar results have been found with muscular endurance. Swimmers were shown to retain shoulder strength after four weeks of the termination of training. There is the possibility that losses in strength, power, and muscular endurance depend upon the activity used for training and testing. This suggests that functional strength may be lost relatively quickly while general strength is retained. For swimmers, it has been shown that strength and muscular endurance gained during a training period may be fully retained for periods of up to six weeks, and approximately 50 percent will be retained for up to a year following the cessation of training.