A question that may have popped into your mind while training is what happens when you stop working out?

If you stopped going to the gym, you stopped doing body weight exercises like pushups and pull-ups, and you stopped being active in general, what would happen? Would you lose all the progress that you work so hard for? And if that’s the case, how fast would you lose it? And how long would it take to get back to where you were before you stopped working out?

What Happens When You Stop Working Out Featured Image

Regardless of whether you’re here because your gym is temporarily shut down or you’re here because you’re just simply considering taking a break from the gym today, we’ll help you understand exactly what happens as the weeks and months go by while you’re not working out. 

Will I Lose Muscle Mass If I Stop Working Out?

So let’s start first with the most obvious: your muscles will begin to shrink. The reason this happens is that muscles will slowly lose their mass over time if you don’t regularly train your muscles and give them the stimulation that they require for maintaining their size.

Maintaining muscle mass costs your body energy, and the human body is very efficient at optimizing its energy usage. So if you stop weight training or using your muscles for even something like calisthenics, your body will start to break down your own muscle mass in order to save some energy expenditure.

Unfortunately, the research on exactly how quickly you’ll lose muscle mass is a little mixed. Some studies suggest that muscle atrophy occurs within just two weeks of not training. Others suggest that atrophy is more likely to occur within three to six weeks of detraining.

The main reason why the results are so mixed is that there are a number of factors that influence how fast you’ll lose muscle. Examples include how much protein you’re consuming, the number of calories you eat on a daily basis, and your general physical activity levels.

Aside from exercise, another thing that exacerbates the situation is the fact that the glycogen stores in your muscles start to decrease very quickly when you stop weightlifting. When you eat carbohydrates, they’re broken down and stored as glycogen, along with a fair amount of water in your muscles. 

So when you stop working out and your muscle glycogen stores go down, your muscles will visibly shrink since there will be less water retention inside of them. This is important to take note of because when scientists measure muscle loss, they look at things like lean body mass, and cross-sectional area.

But the problem is, even though the above methods are useful, they are affected by the number of glycogen stored within your muscles. In other words, you may have not lost muscle, but just because you have less glycogen in your muscles, the measuring methods will interpret that as lost muscle mass when in reality what happened was that you simply stored less glycogen and water into your muscles. 

That’s why we have to take the results of studies that measure muscle loss with a grain of salt. On top of that, as was mentioned, if you maintain your body’s required protein and calorie intake, you’ll retain your muscle size for longer. However, as a general rule of thumb, you can safely assume that true muscle loss will start to happen about three to four weeks after not working out.

Will I Lose Strength If I Stop Working Out?

Now the second thing on our ‘what happens when you stop working out’ list is strength. Since the training causes muscle loss, it’s not surprising that it also decreases your strength as there’s an obvious link between muscle mass and strength. In powerlifters, there’s an 85% to 95% correlation between muscle mass and performance with the major compound lifts such as deadlifts, squats, and the bench press.

And luckily we have a systematic review involving over 27 studies that can help us understand how fast you lose strength after detraining. This review found that maximum strength levels can be maintained for up to three weeks after stopping resistance training. After that, you’ll start experiencing a gradual decline in your strength and the rate of strength losses will actually accelerate even more between five to 16 weeks after stopping exercise.

Given that, it’s not a disaster in terms of strength if you’re forced to take a few weeks off due to an injury or being busy with work or exams. It’s also true that taking a short amount of time off from training will not hurt long-term strength gains.

This can be seen clearly in a study where participants either trained for 24 consecutive weeks or alternated between six-week periods of training and three-week periods of no training. As you can see, the findings of the study were that there was very little difference in strength gains over the long term between the two participating groups.

The bottom line is, taking some time off from training won’t hurt strength too much. However, if those few weeks turn into a month or longer, that’s when you have to start worrying. 

On the bright side, even if you’re forced to take a significant break from weightlifting, you will still be able to take advantage of muscle memory when you start back up again. Even though you will lose muscle and strength after about a month of detraining, the good news is that you can regain both the muscle and the strength much faster than what it originally took to build it in the first place. 

You see, to grow a muscle beyond a particular size, your body has to add myonuclei to that tissue and the Myo nuclei are responsible for regulating most cell functions within a muscle. You can imagine these as the centers of each of your muscle fibers. Now it’s a time-intensive process to add new myonuclei to a muscle, which is why you can’t gain 20 pounds of muscle in a short period of time, like a month. The speed at which your body can add new myonuclei is called Myo nuclear addition and it determines how fast you can actually build muscle.

The good news is that once those myonuclei are in place, they tend to stay there. Research indicates that when it comes to human muscle tissue, even after extended periods of detraining, the same myonuclei will remain there for 15 or more years. And some people even claim that these myonuclei will remain in place for your entire life. This is why it takes much less time to regain lost muscle and strength compared to what it takes to build it in the first place. And that’s why we also have a term known as muscle memory.

Endurance Loss Due to no Longer Working Out

Endurance loss due to no longer working out

Now, going back to the more negative side effects when you stop working out, your endurance will also decrease. One of the big reasons for this is due to the fact that your body will become less efficient at exchanging gases within cells. This is once again due to a number of reasons. For example, when you stop working out, you’ll experience a reduction in the number of alveoli in your lungs. These are tiny air sacs in your lungs that take up the oxygen that you breathe in.

This is why alveoli are known as the workhorses of your respiratory system. Another reason why your endurance will go down is that you’ll have fewer capillaries in your lungs, and this is bad because they supply the alveoli with blood. This is part of what leads to a decrease in blood volume and a reduction in red blood cells. Ultimately, this translates to a reduced ability to carry oxygen to your muscles and clean out the carbon dioxide from your body.

When you stop working out, your heart muscle will also get weaker, which means your heart will pump less blood volume throughout your body, requiring more pumps to achieve well-balanced circulation. This leads to a reduction in your VO2 max, which is the maximum amount of oxygen that your heart, lungs, and muscles can effectively use during exercise. And when I say exercise here, I mean anything from walking to sprinting.

When your VO2 max goes down, you’ll be out of breath sooner and your muscles will fatigue earlier, preventing you from performing in the same way that you could before you took a break from working out. Interestingly enough, according to the studies, your VO2 max will decline slower the more athletic and active you are and have been in the past. Highly trained athletes that stopped training for about a month should only experience about a six to 20% reduction in their VO2 max, still leaving them well above the average person.

Meanwhile, people that recently started training or people who yo-yo back and forth between training for a month and then skipping out for a month, those people will most likely completely reverse any gains they made with their VO2 max and their endurance, bringing them back to square one. 

Sleep Quality Reduction

Next is sleep quality. When you stop working out your sleep quality and quantity will go down. An amazing, yet often overlooked benefit of regular exercise is that it helps you get to sleep faster and stay asleep for longer. That, in turn, offers countless benefits.

A couple of these include improved concentration, enhanced insulin sensitivity, and a reduced risk of heart disease. It’s proven that even people with bad sleeping problems can highly benefit from exercise. For example, one study revolving around people with insomnia found that the participants slept on average, 45 minutes longer per night after four months of regular exercise. On top of that, according to the National Sleep Foundation, exercise improves sleep quality even for people without any sleeping problems like insomnia. Now, unfortunately, it also works the other way around.

If you don’t exercise, you tend to get way worse sleep quality. About 44 out of every 100 people who are inactive experience fairly bad or very bad sleep quality, as opposed to just about 17 out of 100 people who exercise vigorously. So bottom line, if you stop exercising, don’t be surprised if you find it harder to get to sleep and stay asleep. 

Will I Gain Weight If I Stop Working Out?

Another obvious issue that you’ll face when stopping is you’ll be more likely to gain body fat. The main reason for this is pretty straightforward: you’ll burn fewer calories.

Burning less energy means you’ll be more likely to end up in a calorie surplus and gain fat. However, aside from the obvious (you’re no longer burning calories from working out), there are other reasons why you’ll be more likely to gain fat. One is that, like we just talked about, the quality and quantity of your sleep will go down, which increases your chances of gaining fat while also increasing your risk of losing muscle. Another reason why you’ll be more likely to gain weight is if you stop working out is it’s likely that you’ll also start to slack off in other areas of your life, particularly your diet. 

You may have experienced this at some point already. Even though you may feel motivated to eat clean when you’re consistently putting in the work and hitting the gym, that motivation will fade away when you stop exercising. This is because most of us have an all-or-nothing mentality, so when you quit the gym, you may also be more likely to replace your healthy salad with a Big Mac.

Blood Pressure Increases

The next problem that you’ll run into is that your blood pressure will increase. It’s well known that being sedentary is bad for your heart health, and one reason for this is that simply being inactive tends to lead to higher blood pressure.

And if you’ve already been working on decreasing your blood pressure, you may find it alarming that blood pressure will increase back to pretraining levels after just two weeks of stopping exercise. This happens for a couple of reasons, including the fact that being sedentary stiffens arteries, which requires a greater rise in blood pressure to pulse the blood from the heart throughout the rest of the body.

Aside from that, we already mentioned that discontinuing exercise often also causes other bad habits to develop, such as consuming more junk food or just being lazier in general, and both of these are detrimental to heart health. Moving on. 

Mood Decrease Due to Sedentary Lifestyle

When you stop exercising, not only will you be hurting your muscles, but you can also hurt your brain.

There are actually a whole bunch of adverse side effects that will happen to your brain when you stop exercising. For example, your mood may worsen. This is because when you exercise, your body produces endorphins, which are hormones that make you feel good, and your body also produces other happiness-inducing chemicals like dopamine, serotonin, norepinephrine, and endocannabinoids.

The effects of exercise on boosting your mood are so powerful that research even suggests that exercising can be as effective as prescription antidepressants. On the other hand, when you stop working out, you’ll no longer get the same mood-boosting effects, which can create more depression and anxiety in your life.

Blood Flow Reduction to the Brain

The other issue is that blood flow to the brain will decrease. When researchers examined cerebral blood flow and physically fit older adults, they found that just ten days after stopping exercise, blood flow decreased by 20% to 30% in eight brain regions, including the left and right hippocampus, which are both responsible for learning and memory.

So you might become a little less sharp after stopping your workout routine. In fact, according to an interesting study on twins, it’s very likely that you’ll experience more cognitive decline without exercise. In this study, they took ten pairs of identical male twins that exercise regularly, and they had one twin in each pair stay active throughout the study.

Meanwhile, the other twin exercised less after three years. The results showed that the more sedentary twins had less grey matter, which is the tissue in your brain that’s crucial for processing information. So, contrary to the popular quote all brawn and no brain, it actually turns out that brawn and brain can go hand in hand, since exercise doesn’t only help you build muscle, but it also helps support your brain health.


Hopefully, this list of what happens when you stop working out was useful. I’m sure it’s no surprise that I’m hoping that this video convinces you to continue working out or to only take a short break if necessary, because there’s truly nothing out there that can provide the lifestyle benefits that exercise can.

Not only does it add years to your life, but it also adds life to your years. Taking a short three-week break or a month off the gym can often lead to a downward spiral where you don’t find yourself back in the gym until 15 years later. I’ve met many people that have regretted taking long periods of time off as I progressed in my finished journey since I was 13.

So we encourage you to treat exercise like brushing your teeth. Even if you’re stuck without a gym, there are plenty of things you can do at home or outside. So keep going, and don’t lose motivation if you have to take some time off!

About the Author: Jason Chapman

Jason Chapman has a degree in Exercise Science and is a personal trainer with 10+ years of experience in fitness and strength coaching. Jason spends his time with BodyCapable researching the latest strength training trends and writing science-backed, informative content. Jason likes to spend his spare time hiking, traveling, and of course training!