Share on Pinterest Everyone has skipped a workout at some point — don’t let anybody tell you different. At Greatist, we’re firm believers in cutting yourself some slack and taking time off from exercise when you need to. But we also know how easily 3 days off can snowball into 6, then 10. Before you know it, you’re asking that question we’ve all asked when the gym feels like a distant memory: How long does it take to lose my fitness? First, it’s important to remember that taking time off now and again is a good thing. Exercise inflicts a degree of stress on your body. Any good workout program includes a heck of a lot of rest days, especially if the exercise is very intense. And there are benefits to both “active recovery” and complete rest. That said, “use it or lose it” is pretty much the rule. But exactly how much fitness you’ll “lose” depends on the length of your break and how fit you were to begin with.

If you exercise on the regular It’s a lot easier to bounce back from time off if you’re someone who exercises five or six times a week or if you’ve been exercising for a while. In fact, if you have that strong of an exercise habit, scientists are quite willing to drop you into the “athlete” category. Generally speaking, if you’ve been working out several times a week for more than a year, your muscle memory is solid. A 2019 study showed that skeletal muscles may stick around even when other muscles shrink (called atrophy). Schwartz LM. (2019). Skeletal muscles do not undergo apoptosis during either atrophy or programmed cell death-Revisiting the myonuclear domain hypothesis. DOI: 10.3389/fphys.2018.01887 It’s like having a head start once you get back to training. Your body can then facilitate faster growth of your muscles (called hypertrophy). This research was done on rodents and insects, so more studies are needed, but it’s fascinating stuff. Muscle memory aside, your fitness can still deteriorate at different rates depending on whether you’re looking at strength or cardiovascular losses. Strength loss For most people, strength loss occurs after two to three weeks of inactivity, says Molly Galbraith, a certified strength and conditioning specialist. But it depends on why you take the break. “If you are sick, your body is overstressed, so you’ll start to lose strength after two to three weeks,” she says. Science agrees. A 2017 study showed that men who did resistance training held on to muscle strength after a two-week break. Hwang PS, et al. (2017). Resistance training–induced elevations in muscular strength in trained men are maintained after 2 weeks of detraining and not differentially affected by whey protein supplementation. DOI: 10.1519/JSC.0000000000001807 But by three weeks without a sweat sesh, it could be a different story. A 2013 study showed that athletes will start to lose muscle strength after three weeks without a workout, also called “detraining.” McMaster DT, et al. (2013). The development, retention and decay rates of strength and power in elite rugby union, rugby league and American football: A systematic review. DOI: 10.1007/s40279-013-0031-3 And the more muscle you have, the more you stand to lose. A 2015 study found that active young adults lost one-third of their leg strength after just two weeks of inactivity. Vigelsø A, et al. (2015). Six weeks’ aerobic retraining after two weeks’ immobilization restores leg lean mass and aerobic capacity but does not fully rehabilitate leg strength in young and older men. DOI: 10.2340/16501977-1961 Given how quickly muscle loss can happen, try to get in at least a little movement during your fitness break, if at all possible. “If you’re not sick, and especially if you’re able to get in some movement and light exercise, you can probably take three, four, even five weeks off without significant strength loss,” says Galbraith. Cardio loss So, what about all the cardio lovers out there who are more concerned with the strength of their heart and lungs? Sadly, we lose this kind of conditioning a little more quickly than we lose strength. The research on cardio loss is a bit older. A landmark 1984 study showed that after 12 days of inactivity, VO 2 max dropped by 7 percent and enzymes in the blood associated with endurance performance decreased by 50 percent. Coyle EF, et al. (1984). Time course of loss of adaptations after stopping prolonged intense endurance training. DOI: 10.1152/jappl.1984.57.6.1857 A 1993 study of endurance cyclists found that four weeks of inactivity resulted in a 20 percent decrease of their VO 2 max, which measures a person’s maximum capacity to take in, transport, and use oxygen during exercise. Madsen K, et al. (1993). Effects of detraining on endurance capacity and metabolic changes during prolonged exhaustive exercise. DOI: 10.1152/jappl.1993.75.4.1444 In 2017, researchers analyzed the performance levels of soccer referees in the period between the end of the competitive season and the preseason. They noted a significant decrease in sprinting ability, cardiovascular fitness, and distance covered. Castillo D, et al. (2017). Effects of the off-season period on field and assistant soccer referees’ physical performance. DOI: 10.1515/hukin-2017-0033 But keep your chin up. While your cardio conditioning does fall faster than your strength, it’s easier to regain, Galbraith says. So get back on that horse, cowboy.

If you’re newer to exercise Congratulations on your newish exercise habit! If you’ve hit pause on your trips to the gym, don’t take too long to hit play again. Consistency is key for building new habits, and it’s as true for the body as it is for the mind: If your body hasn’t been enjoying exercise for long, it can be easier to lose the progress you’ve made. Strength loss As far as strength goes, it’s best not to be too concerned about losing your headway, as those famous “newbie gains” make it somewhat easier to retain strength. A 2013 study showed that nonathletes who trained their legs just once a week for three weeks were able to maintain their strength after two weeks of detraining. Ogasawara R, et al. (2013). Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training. DOI: 10.1007/s00421-012-2511-9 In a 2011 study, previously untrained folks who took a 3-week break in the middle of a 15-week bench press program finished the course with strength levels similar to those of people who didn’t take a break at all. Ogasawara R, et al. (2011). Effects of periodic and continued resistance training on muscle CSA and strength in previously untrained men. DOI: 10.1111/j.1475-097X.2011.01031.x It’s also worth noting that among newbies, eccentric strength — that is, the strength you use when lengthening a muscle or lowering a weight — may be harder to lose than concentric strength, which you use when contracting a muscle. A 2005 study of 13 previously untrained men found that three months after ending a three-month training program, they had maintained their eccentric strength gains but not their concentric strength. Andersen LL, et al. (2005). Neuromuscular adaptations to detraining following resistance training in previously untrained subjects. DOI: 10.1007/s00421-004-1297-9 Cardio loss Once again, cardio is a little more sensitive to time off. One of the best studies on the effects of detraining is from 2001. It showed that VO 2 max gains made in the previous two months are completely lost after four weeks of inactivity. Mujika I, et al. (2001). Cardiorespiratory and metabolic characteristics of detraining in humans. https://journals.lww.com/acsm-msse/Fulltext/2001/03000/Cardiorespiratory_and_metabolic_characteristics_of.13.aspx A 2018 study of recreational runners found that after four weeks of detraining, the benefits of “athlete’s heart” (which are normal adaptations to training) regressed. By eight weeks of detraining, performance on the treadmill significantly declined. Pedlar CR, et al. (2018). Cardiovascular response to prescribed detraining among recreational athletes. DOI: 10.1152/japplphysiol.00911.2017

Other factors While your fitness level is key to how quickly you get back to your fitness baseline, a few other variables also come into play. A 2000 study found that age plays a role in bounce-back time. Among 41 study participants who were either 20 to 30 years old or 65 to 75 years old, the older people lost strength almost twice as fast as the younger people during a six-month “detraining” period. Lemmer JT, et al. (2000). Age and gender responses to strength training and detraining. https://www.ncbi.nlm.nih.gov/pubmed/10949019 Children have a serious advantage. A 2018 study found that 10- to 13-year-olds were able to hang on to fitness gains after four weeks of detraining. Chaouachi A, et al. (2018). Global training effects of trained and untrained muscles with youth can be maintained during 4 weeks of detraining. DOI: 10.1519/JSC.0000000000002606 And again, why you’re taking the break is also a factor. When scientists injected inactive volunteers with hormones that mimicked the stress of trauma or illness, they had a 28 percent decrease in strength over 28 days — a higher rate than average. Paddon-Jones D, et al. (2006). Atrophy and impaired muscle protein synthesis during prolonged inactivity and stress. DOI: 10.1210/jc.2006-0651