Getting back to the gym after taking a small hiatus can feel like lifting weights for the very first time. And if you’ve ever tried to run after taking some time off, you know how painful that can be. The change is real, and pretty discouraging—physically and mentally. But how much is that really throwing you off your fitness goal? And how long is too long before you’ve disrupted all that hard work you put in working out?
Here’s what happens to your body when you fall off the workout wagon (hey, life happens), and how much progress you really lose.
Skipping workouts for a few days, or even a week, really isn’t going to do much.
In fact, sometimes, your body may need it. “For most people that are exercising regularly and have a moderate to solid conditioning level [you work out four to six times a week], a week off is an opportunity to take a break and refresh the mind and body,” Cris Dobrosielski C.S.C.S., C.P.T., consultant and spokesperson for American Council on Exercise and founder of Monumental Results Inc., tells SELF. And assuming you don’t make it a regular habit, you don’t need to stress about falling out of shape.
The biggest risk in taking a week off is really more mental. “For the beginner, the routine of exercise is a huge key, and for this person getting motivated after a week off might be more difficult,” says Steve Ball, Ph.D., state specialist and associate professor of nutrition and exercise physiology at the University of Missouri. “Some quit and never start again.” Recognize that you’ve had to hit the pause button, and if you need a little extra motivation to pick things back up when your schedule allows.
But within about two weeks of inactivity, aerobic conditioning starts to noticeably decline.
Aerobic exercise (a long, easy run, for example) works your heart and lungs. “VO2 max basically measures a person’s capacity to take in, transport, and then use oxygen during exercise,” explains Tara Plusch, senior registered clinical exercise physiologist at NYU Langone Medical Center’s Rusk Rehabilitation. The more you train, the more efficient your lungs and heart become at delivering fresh oxygen and blood to your body during exercise, and the better your VO2 max.
When you stop exercising, both VO2 max and the heart’s ability to pump blood efficiently start to decline. The exact rate will vary, but studies suggest that after about two weeks of inactivity you’ll notice some changes. “It’s been shown in endurance athletes that by four weeks [of inactivity] there’s a 20 percent decrease in VO2,” Plusch says. “There are studies that show even at the 12-day mark, there’s a seven percent decrease in VO2 max.” When it comes to the average gym goer, experts say you’ll start to feel those changes around the two-week mark. (But Ball notes that measurable detraining, for some, can even start as soon as 10 days from the cessation of exercise.)
When it comes to strength training, detraining isn’t quite as noticeable.
There’s a lot of conflicting research when it comes to losing muscle mass, because the rates will vary based on your age, sex, and your beginning muscle mass, which will differ greatly if you’re an endurance athlete versus a powerlifter.
But typically, for a regular exerciser who lifts a few times a week, taking some time off won’t really cause much loss. “Strength and muscle mass change very little in a couple of weeks, so not a lot happens,” Dobrosielski says. “A person who has put on a significant amount of muscle mass can go anywhere from four to 10 weeks and still might look good, and come back and perform reasonably well.” So while there’s a decline, it’s less substantial than it is with your cardiovascular fitness.Research suggests that muscle strength fibers remain unchanged after a month of inactivity, but you may see a loss in sport-specific power.
But it’s totally normal to feel weaker (which is why you want to ease back into your training routine after taking time off). Both your mind and muscle are a little thrown off after a hiatus. It takes coordination, and literal muscle memory, to lift, so feeling out of sync and not as confident can make lifting heavy weights feel even harder.
The fitter you are, the sooner you’ll notice signs of detraining. But the less likely you are to decline back to where you started.
Seems unfair, right? But since your body is more adapted to constant training at a higher level, you’ll notice a difference a lot sooner than someone who works out more irregularly or at a much lower intensity. And this holds true for both aerobic activity and strength training.
“The more highly trained runner will see some aerobic drop off in that first one to three weeks,” Dobrosielski says. But while you’ll notice it more at first, after that initial drop off, losses will be more gradual than in a beginner. “Someone less trained will not show a whole lot of change in that first one-to-three-week period, but after four to eight weeks, that fitness ability or aerobic capability is more likely to go back to zero.” More rigorous exercises can expect their losses to plateau after about four to six weeks, keeping their abilities above baseline for a lot longer than the beginner.
Factors like age and sex can also impact your rate of detraining—for example, older women have been shown to lose muscle mass quicker than other demographic groups.
It’s better to get in a few short, high-intensity workouts than skipping completely.
Yep, a little something is better than nothing—if you can. Even if you’re not declining back to zero, your losses can be significant. An aerobically fit athlete could experience a 25 percent decline from their physical prime (when measuring with markers like VO2) within a few months, Ball says. “Typically the longer the break the greater the effect. Also, it often takes longer to get it back than the time you took off.”
So instead of skipping a few weeks or months of exercise, Dobrosielski recommends cutting back a number of sessions you’re logging, but upping your intensity on the days you can get a workout in. “If you’re squeezed for time, just work a little harder on the days you’re able to go to the gym,” he suggests. Ultimately you want to strive for a well-balanced training routine (here’s what that looks like) that you can sustain for a long time. So if you need to tweak and modify your schedule every now and then in order to stick with it, that’s fine. Just bounce back when you can.