In the ideal world, you’d exercise regularly throughout your life. But sometimes life intervenes and you have to take time off. Whether it is a family crisis, a work obligation, an illness or an injury, sometimes you end up on the sidelines. Unfortunately, you can’t become fit and expect to maintain fitness gains if you stop working out. If you stop exercising for a significant period of time, your body gradually loses the adaptations that made it so easy to bench-press 120 pounds or run an 8-minute mile. This is called the detraining effect, and it basically means “you lose it when you don’t use it.”
The Detraining Effect: How Long Does It Take to Get Out of Shape?
How quickly you detrain depends on the level of fitness you achieved, how long you’ve been training and the length of the break you take from exercise. Studies show that athletes and seasoned exercisers lose their fitness gains more slowly than exercise newbies. In one study, participants who had exercised regularly for only 2 months lost all of their fitness gains after 8 weeks of a sedentary lifestyle. Participants that had been training for a year lost only half their gains after 3 months of no training.
How fast do you lose strength gains when you stop doing resistance training? In one study, men who lifted heavy weight lost 12% of their muscle strength after only 2 weeks of being sedentary. Their type 2 muscle fibers also contracted by 6.4%. The good news is it may be easier to recoup those gains the second time around due to the phenomenon of “muscle memory.” This simply means the neural circuitry is still there to stimulate muscle growth; you just need to reactivate it by lifting.
The Good News about Exercise and Detraining
It’s pretty discouraging to think all of the fitness gains you worked so hard to achieve could be cut by half or more in only a few months. But there is some good news. If you reduce how often you train rather than sitting in an easy chair, you can maintain your gains longer. With resistance training, decreasing your training to only one to two times a week will maintain most of your strength gains as long as you lift with the same intensity.
In terms of aerobic fitness, most people will lose their endurance training benefits in a few months if they’re completely inactive. Declines in aerobic fitness can be seen as early as 10 days after being sedentary. But if you can still fit in a few, short aerobic workouts a week, you can maintain some of your fitness gains. This is especially true if you exercise at a high-intensity during those sessions. The key to preserving most of your gains is to keep the intensity high even if you cut back on the time or frequency of the sessions.
Keep Exercising Even if You Have to Cut Back
Everyone needs a day or even a few days off from exercise and such brief breaks can be beneficial by allowing the body to rest. It’s easy to get burned out mentally if you work out intensely every day. You won’t lose your fitness gains if you allow your body to rest and recover for a few days. If you have to take a longer break, make time for a few intense exercise sessions to maintain your fitness if you can.
Exercise Physiology. Fifth edition. 2001.