How long does it take to lose muscle if you stop training? What the science says
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Two weeks away from the gym will not wipe out your muscle: in trained men, leg strength did not drop at all. When you start to lose it, what goes first and why regaining it is faster than building it.
A holiday, a work trip, a bout of flu or simply a very busy spell. Sooner or later everyone who trains spends a few days or weeks away from the gym, and almost always with the same worry: am I losing what took so much effort to build?
The short answer is: much less than it seems, and much more slowly. In this guide you will see what happens in your muscles after one, two, four or more weeks without training, what goes first, why the muscle you have built "remembers" and how much training it takes to keep it when you cannot train as usual.
Two weeks without training: almost nothing
Hwang and colleagues (2017) tested exactly that situation. Twenty young men with resistance training experience trained 4 days a week for 4 weeks, stopped training for 2 weeks and then returned for another 4. After the break, leg press strength did not drop in either of the study's two groups, and lean mass measured by DEXA was maintained.
Other data point the same way. Ogasawara and colleagues (2013) compared, over 24 weeks, men who trained the bench press without a break with others who did cycles of 6 weeks of training and 3 weeks off. At the end, the growth of the chest and triceps and the strength gains were similar in both groups: the 3-week breaks did not cost them their progress, because on returning they regained momentum very quickly.
The key idea: if you train regularly, one or two weeks off will not cost you any noticeable muscle. And the little you do notice, mostly in how you feel and in your endurance, comes back as soon as you resume.
Stopping training is not the same as being immobilised
There is one situation in which muscle is lost quickly: when it is not used at all. Wall and colleagues (2014) put one leg of young, healthy men in a cast. After just 5 days, quadriceps cross-sectional area had fallen by 3.5% and strength by 9%; after 14 days, by 8.4% and 22.9%.
This is not what happens on a holiday where you walk, climb stairs and move normally. It is what happens after an injury with immobilisation, an operation or several days in bed. In those cases, moving again as soon as the doctor allows it, and eating enough protein, is what helps most.
What you lose first when you stop training: muscle or strength
Not everything goes at the same pace. Mujika and Padilla's review (2000) on the first 4 weeks of insufficient training describes aerobic capacity as the first thing to fall: maximal oxygen uptake and blood volume drop quickly in highly trained athletes. In the muscle, the changes in fibre size achieved through recent training may be reversed, but the loss of strength is limited.
| Situation | What happened | Study |
|---|---|---|
| 5 days with the leg immobilised | Quadriceps −3.5%, strength −9% | Wall et al., 2014 |
| 14 days with the leg immobilised | Quadriceps −8.4%, strength −22.9% | Wall et al., 2014 |
| 2 weeks without training, trained men | Leg strength unchanged and lean mass maintained | Hwang et al., 2017 |
| 3-week breaks between 6-week blocks | After 24 weeks, same muscle and strength as training without a break | Ogasawara et al., 2013 |
| Less than 4 weeks of insufficient training | Aerobic capacity falls fast; strength, only a little | Mujika and Padilla, 2000 |
| 30-32 weeks without training, trained women | Fibre size barely changed; strength fell, but not back to the starting level | Staron et al., 1991 |
The practical order is this: first you notice you get out of breath sooner, then that you move a little less weight, and the last thing to change is the size of the muscle.
Muscle memory is real
Staron and colleagues (1991) followed women who had trained their legs for 20 weeks and then spent 30 to 32 weeks without doing so. The break barely changed the size of their fibres, and although strength fell, it did not return to the starting level. When they resumed training, 6 weeks were enough for their fast fibres to grow significantly again. The authors concluded that part of what is gained is kept for a long time and makes it easier to get back into shape quickly.
Two explanations are being studied:
- The nuclei stay. Muscle fibres gain nuclei as they grow. Bruusgaard and colleagues (2010) saw in mice that these nuclei were not lost even with severe, prolonged atrophy, and that muscle that had them resisted loss better. It is an animal study, but it offers a plausible mechanism.
- The genes "remember". Seaborne and colleagues (2018) studied in people what happens when they train, stop until the muscle returns to its starting size and train again. They found changes in the way certain genes are switched on that persisted through the break, and the largest gains in muscle mass came in the second training phase.
In practice: regaining muscle you once had is considerably faster than building it the first time.
How much training is enough to lose nothing
If you know you are going to go through a period with little time, the good news is that maintaining costs much less than progressing. Bickel, Cross and Bamman (2011) trained 70 adults 3 days a week for 16 weeks and then split them for 32 weeks into three groups: stop training, or continue with one third or one ninth of the previous volume. In the young participants, aged 20 to 35, both maintenance plans preserved the muscle gained, and with one third it even kept growing a little. In older adults, aged 60 to 75, it was not enough: they needed more volume so as not to lose it. The strength gained was retained fairly well even in those who stopped training.
| Situation | What to do |
|---|---|
| A 1-2 week break | Nothing special: rest, move and eat well. You will come back the same |
| Little time for weeks, under 60 | 1 full-body session a week with a few hard sets maintains muscle |
| Little time for weeks, over 60 | Better 2 sessions: with less volume, muscle is not kept as well |
| No gym | Bodyweight exercises close to failure, at home or in the hotel |
| Injury or immobilisation | Move what you can, eat enough protein and follow the doctor's advice |
If you are going to stop, how to lose as little as possible
- Eat enough protein. It is what best protects muscle when you train less. You have the amounts in how much protein you need a day.
- Keep moving. Walking and climbing stairs do not replace training, but they avoid the scenario of total inactivity, which is the one that speeds up loss.
- Do a short session if you can. Push-ups, squats and lunges close to failure in 20-30 minutes are enough. There is an example in the home workout with no equipment.
- Sleep well. Sleep is part of recovery, even when you train little. More in sleep and performance.
How to come back after a break
The typical mistake is to come back with the same loads and volume as the last day, as if nothing had happened. Muscle comes back quickly, but tendons and joints need a few days to readapt, and the soreness after the first session can be strong.
- First week: fewer sets than usual and loads that leave several reps in reserve.
- Second week: go back to your normal volume if you have recovered well between sessions.
- From then on: increase the loads progressively. If the break was short, within a few weeks you will be where you left off.
If the break was long, start as if it were the beginning of a new block: in the Progrevia routine generator, choose your level and week 1 of the mesocycle, which is the one with base volume and more moderate effort.
Common mistakes
- Panicking after a week without training. You have not lost muscle; at most, some glycogen and water, which show in the mirror and on the scale but come back within days.
- Trying to make up for the break by training twice as much. It only piles up fatigue. Pick up your plan where you left it.
- Cutting protein "because I am not training". That is exactly when it matters most.
- Coming back at your maximum loads. It is the easiest way to get injured in the first week.
Conclusion
Stopping training for one or two weeks does not cost you any noticeable muscle: in trained men, two weeks lowered neither strength nor lean mass, and three-week breaks did not slow progress at six months. What does make you lose muscle quickly is total immobilisation. If you are going to go through a period with little time, one weekly session with a few hard sets maintains what you have gained in young adults, and older adults need a little more. And if you have already lost it, muscle memory makes regaining it faster than the first time.
- Hwang PS, Andre TL, McKinley-Barnard SK, et al. 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. Journal of Strength and Conditioning Research. 2017;31(4):869-881.
- Ogasawara R, Yasuda T, Ishii N, Abe T. Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training. European Journal of Applied Physiology. 2013;113(4):975-985.
- Wall BT, Dirks ML, Snijders T, et al. Substantial skeletal muscle loss occurs during only 5 days of disuse. Acta Physiologica. 2014;210(3):600-611.
- Mujika I, Padilla S. Detraining: loss of training-induced physiological and performance adaptations. Part I: short term insufficient training stimulus. Sports Medicine. 2000;30(2):79-87.
- Staron RS, Leonardi MJ, Karapondo DL, et al. Strength and skeletal muscle adaptations in heavy-resistance-trained women after detraining and retraining. Journal of Applied Physiology. 1991;70(2):631-640.
- Bruusgaard JC, Johansen IB, Egner IM, Rana ZA, Gundersen K. Myonuclei acquired by overload exercise precede hypertrophy and are not lost on detraining. Proceedings of the National Academy of Sciences of the USA. 2010;107(34):15111-15116.
- Seaborne RA, Strauss J, Cocks M, et al. Human skeletal muscle possesses an epigenetic memory of hypertrophy. Scientific Reports. 2018;8(1):1898.
- Bickel CS, Cross JM, Bamman MM. Exercise dosing to retain resistance training adaptations in young and older adults. Medicine & Science in Sports & Exercise. 2011;43(7):1177-1187.
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Frequently asked questions
How long does it take to lose muscle if you stop training?
Longer than is usually thought. In Hwang's study (2017), trained men who stopped for 2 weeks lost no leg strength and kept their lean mass. Rapid loss happens with total immobilisation: 5 days with one leg in a cast reduced the quadriceps by 3.5% (Wall, 2014).
Do you lose muscle in a week without going to the gym?
Not noticeably if you keep moving normally and eating well. What shows first is some water and glycogen, which come back within a few days of resuming, and some aerobic capacity.
Is muscle memory real?
Yes. In Staron (1991), women who stopped training for more than 30 weeks kept much of their fibre size, and 6 weeks of training were enough to make them grow again. Studies point to muscle nuclei that are kept (in mice) and to a memory in how genes are switched on (in people).
How much do you need to train to maintain muscle?
Much less than to progress. In Bickel (2011), adults aged 20 to 35 kept the muscle they had gained training with one third or even one ninth of the previous volume. Those aged 60 to 75 needed more volume so as not to lose it.
How should you get back to training after a break?
With fewer sets and lighter loads in the first week, returning to normal volume in the second if you recover well. Muscle comes back quickly, but tendons and joints need a few days to readapt.
Informational content based on the available scientific evidence: it does not replace advice from a healthcare professional. If you have an injury or a medical condition, or are pregnant, check with one before changing your training or diet.
