What happens to the body when you stop exercising

What happens to the muscles

If you do not use the potential of the muscles, the body does not waste calories to maintain them. However, you do not start to lose muscle mass immediately.

Short break up to two weeks

One study found that after two weeks of rest, the number of fast muscle fibers decreased by 6.4%. Perhaps such changes are related to the amount of glycogen, which binds water and retains it in the muscles, which increases their volume. Due to lack of training, the amount of glycogen decreases and the size of the muscles decreases.

However, other research suggests that if you start exercising again, your water and glycogen stores will quickly replenish.

Well-trained athletes need not be afraid of short breaks. A 2017 study confirmed that they did not lose muscle mass after two weeks without training. A short break can even be beneficial. The study showed that after two weeks of inactivity, the concentration of growth hormone increases by 58%, testosterone - by 19.2%, and the level of cortisol in blood plasma drops by 21.5%. This creates excellent conditions for muscle growth, so two weeks off can have a positive effect on results.

Long break

The study found that after seven weeks of no training, overall muscle wasting in powerlifters was 37.1%.

After two months, the number of rapidly contracting muscle fibers decreases in strength athletes, and in those who train for endurance, it increases. In long distance runners and cyclists, the number of fast muscle fibers increases by 14% eight weeks after stopping training. In endurance athletes, muscle loss without training occurs much more slowly - up to 12 weeks unchanged.

Women lose muscle mass faster. A study in young women showed that the pounds of muscle mass gained in seven weeks of strength training disappeared after seven weeks without training.

What's going on with force

After two weeks without training, trained athletes maintain a one-rep maximum in the bench press and squat with a weight, there is no change in isometric strength. After four weeks without training, there are also no major changes in strength and endurance.

For beginners, the loss of strength indicators begins no earlier than after three weeks of rest. In one study, a group of people who trained for six weeks, after a three week break, stayed the same one-rep maximum.

Unlike trained athletes, beginners have relatively little long-term loss of strength. The study found that 24 weeks without training reduced participants' 1RMs by 6% and isometric strength by 12%. For athletes and sprinters, strength performance decreases by 7-12% after 12 weeks without training, that is, twice as fast.

The method of training also affects the rate of loss of strength. The study found that athletes whose workouts included more eccentric movements lost strength much more slowly than athletes with predominantly concentric movements in training.

How quickly do you lose stamina

There are many ways to measure the endurance of an athlete. One of the most popular is the maximum amount of oxygen per kilogram of body weight that you can absorb in a minute (VO2max).

When you stop exercising, VO2max drops quite quickly. For beginners, it decreases to pre-workout levels after just four weeks, while for well-trained athletes, this process takes place more slowly. One study found that trained runners dropped 4% in VO2max after two weeks of inactivity. It takes up to 6–20% in four weeks.

In trained athletes, endurance decreases by 4–25% after 3–4 weeks of inactivity. However, even after this time, it still remains higher than that of people who do little sports.

Research has shown that athletes with high intensity training remain 12-17% higher in VO2max than untrained people even after 84 days of inactivity.

Conclusion

Several conclusions can be drawn:

In the first two weeks without exercise, strength and muscle mass do not change. Depending on the level of training, endurance can decrease by 4–25%, but when training is resumed, the lost indicators are quickly restored.
Taking a short break can be beneficial because after two weeks the concentration of growth hormone and testosterone increases in the body.
The more eccentric exercises you do, the longer you will maintain strength after you stop exercising.
The harder and longer you train, the longer it will take for you to decrease strength and endurance.