The principle of reversibility, as applied to exercise and physical training, means: if you don’t use it, you lose it. This principle is well grounded in exercise science and is closely related to the biological principle of use and disuse. (1)

While rest periods are necessary for recovery after workouts, long rest intervals reduce fitness. The physiological effects of physical training diminish over time, causing the body to return to its pre-training condition.

Detraining occurs within a relatively short period of time after you stop exercising. Only about 10% of strength is lost 8 weeks after training stops, but 30-40% of muscular endurance is lost over the same period of time. (two)

The Reversibility Principle does not apply to skill retention. The effects of stopping the practice of motor skills, such as weight training exercises or sports skills, are very different.

A skill once learned is never forgotten, especially if it was learned well. Coordination appears to be stored in long-term motor memory and remains nearly perfect for decades, particularly for continuous skills (eg, bicycling, swimming). If you stop training, over time you will lose strength, endurance, and flexibility, but you will remember how to perform the skills involved in performing exercises and activities. (3)

Tips on how to apply the principle of reversibility

1. After long rest intervals, begin a conditioning program to rebuild your base strength and endurance.

2. For sports, take an active break to minimize the effects of detraining during the off-season.

3. Increase exercise gradually and gradually after a long break. Be patient to get back to your previous fitness level.

4. Don’t attempt to lift heavy loads without proper conditioning after a long rest. You’ll remember how to perform the lifts correctly, but you can injure yourself if you overestimate how much weight you can lift.

5. Emphasize stretching exercises to restore joint flexibility. This is particularly important for older adults who participate in senior sports.

References

1. Powers, S.K., Dodd, S.L., Noland, V.J. (2006). Fitness and Total Wellness (4th ed.). San Francisco: Pearson Education.

2.Costill, D. & Richardson, A. (1993). Manual of sports medicine: Swimming. London: Blackwell Publishing.

3. Schmidt, RA and Wrisberg, CA (2000). Motor Learning and Performance: A Problem-Based Approach to Learning (2nd ed.). Champaign, IL: Human Kinetics.