Even the most dedicated gym-goers sometimes take an extended break from working out, whether due to vacation, illness, or just life getting in the way. What happens to your body after depends on factors like fitness level, diet, and the length of your break, but most people experience some common short- and long-term changes.
1. Mood Changes
A worsened mood is probably the first thing you’ll notice within a few days since your last workout. You might feel more crabby, stressed, and fatigued.
“There’s an absolute mental, emotional, psychological benefit to exercising—an acute release in neurotransmitters that make us feel better,” Luke Carlson, MS, a certified exercise physiologist and founder and CEO of Discover Strength in Minneapolis, told Health. “So it is very true that if we go a couple days without a workout, we’re not experiencing those. We might feel like we’re in a funk.”
2. Sleep Disruptions
Once you stop working out, you may find you’re having a harder time going to sleep, Joey Masri, DPT, OCS, CSCS, a board-certified orthopedic physical therapist based in Miami, told Health.
That’s because exercise improves sleep. Research has found that people who exercise sleep more and better than those who don’t. Physical activity also helps regulate circadian rhythm to promote quality sleep.
3. Feeling Sluggish
Not only can your sleep quality take a hit when you stop exercising, but rising blood sugar levels may also leave you feeling more sluggish.
Exercise helps lower blood glucose levels because your muscles use glucose for energy when they contract. But when you stop exercising, that glucose is more likely to be stored. Blood sugar levels can start rising within just a few days, and within a week, you might notice signs of less stable blood sugar, such as fatigue, craving sweets more often, or feeling thirstier than usual, Masri said.
Over time, your body may also become less sensitive to insulin, which can affect fat storage and body composition—and increase the risk of type 2 diabetes.
4. Decline in Cardiovascular Fitness
You’ll notice cardiovascular changes before strength or muscle loss. After about two weeks without exercise, your VO₂ max will likely begin to decline.
VO₂ max—how much oxygen your body can absorb and use during exercise—is one of the main measures of cardiovascular fitness. The higher your VO₂ max, the better.
5. Changes to Body Composition
After several weeks, your metabolism will start to slow down, Masri said. “The general understanding is that the more active you are, the higher your metabolism is going to be,” he explained.
Because of that, you’ll likely notice your body composition starting to shift after three to four weeks of no exercise. “The weight on the scale might change,” he said. “Assuming you’re eating the same as you did when you did exercise, you’ll probably start gaining weight. Other people may actually start noticing they’re losing weight because they’re not exercising. Without exercise, their body doesn’t have that stimulus to tell them, ‘Hey, please eat to fuel this.’”
6. Decreased Strength
Missing a handful of workouts probably won’t change lean muscle tissue, muscle strength, or bone mineral density, Carlson said.
But around that 14- to 21-day mark, you may begin to lose some strength and notice muscle shrinking. These changes will become even more pronounced after four to six weeks, Masri added.
7. More Stiffness and Less Flexibility
At that four- to six-week mark, you might also start feeling more achy. “Your joints get stiff, your muscles get tighter,” Masri said. “Things just feel cruddy, not as smooth. You don’t feel as flexible anymore.”
What happens to your body after taking an extended break from exercise depends on factors like size, diet, and overall fitness level—but most people can expect some changes. In the short term, you might be moodier and sleep less soundly. Over time, you may notice a decline in cardiovascular fitness, reduced muscle size, and increased stiffness.
