How Long Can You Go Without Lifting Weights and Not Lose Muscle?

Muscle atrophy can occur in as little as a week and a half.

1.5 to 2 Weeks

As soon as you stop lifting weights, the body's muscle-building enzymes can break down. Muscles start to atrophy in one and a half to two weeks, according to Columbia University's "Go Ask Alice" Health Q&A service. You can lose nearly all of your gains in two weeks if you have not trained for long.

Depends on How Active You Still Are

How fast your muscles start atrophy after you stop lifting weights depends on how active you remain in your life, according the University of Maryland Medical Center. In extreme cases, such as those of bedridden people or astronauts in space, atrophy occurs within a few days.

Bottom Line

Your muscles should begin to atrophy within two weeks of "detraining." Muscles have "memory," however, and you should experience rapid gains as soon as start training again. Some coaches even have athletes cease training for 2 to 4 weeks to rest and so the athlete can come back stronger with the resumption of training.

References

• Columbia University: Use it or lose it? The facts of detraining
• Maryland Medical Center: Muscle Atrophy