How quickly do you lose muscle?
January 15, 2024

How quickly do you lose muscle?

Patrick D.

Your body is amazing! It’s made up of about three trillion cells, 79 separate organs, eleven systems, 206 bones, and over 600 named muscles. It’s capable of impressive feats, from mountain climbing to walking a tight rope to fighting off diseases.

And yet, despite this, your body is relatively easy to maintain. Provide it with the correct fuel (aka food), stay hydrated, get enough sleep, and get regular movement, and it should provide you with a lifetime of faithful service.

Cardio is often described as the most important and beneficial type of exercise when it comes to fitness. That makes a certain amount of sense because, of all the muscles in the human body, the heart is arguably the most critical. After all, it’s the one that pumps oxygenated blood around your body, keeping you alive.

So, how quickly do you lose muscle mass? The answer depends on several factors, including your stress and activity levels, diet, and age. And while there isn’t much you can do about Old Father Time, other things like exercise and what you eat are all within your control.

In this article, we’ll look at the role muscles play, what contributes to muscle loss, how losing muscles impacts our body, and ways to reduce our risk of muscle loss. 

Roles muscles play

Muscles play a critical role in every aspect of life. There are three types of muscle tissue – cardiac, smooth, and skeletal. Our focus today is skeletal muscles.

Skeletal muscle is voluntary, which means we have conscious control over it. However, muscles can act involuntarily too. Try not to blink when something comes close to your eyes or move your hand away from something hot. We have no control over reflexive muscle actions.


Muscles are attached to bones via tendons and act as pulleys to move your body. Every movement you make results from muscles contracting, relaxing, and affecting your skeleton. In fact, the interaction of muscles and bones is so closely connected that they are collectively referred to as the musculoskeletal system.


Posture is the alignment of your joints, and it can be good or bad. Good posture requires very little muscular activity, while poor posture puts a lot more strain on your muscles and joints. Whether you’ve got good or bad posture, it’s your muscles that are responsible for keeping your head up, your spine straight, and your knees from collapsing under you when you are standing still. 


You can’t fire a cannon out of a canoe, or so the saying goes. That’s because the force of the cannon would tip your boat over (we haven’t tested that one out ourselves). The same is true of your body. Seemingly unrelated muscles contract to provide other muscle groups a stable platform to work from. For example, when you use your arms to lift something heavy, your legs and core brace so that you don’t simply collapse under the load.

Temperature regulation 

If you’re cold, your muscles generate heat by shivering. The colder you are, the more intensely you tend to shiver. This might not be the most crucial function of muscles, but it’s rather interesting!


Muscle has a massive impact on your shape. You can sculpt your body by training with weights and building bigger muscles. This doesn’t mean that everyone who lifts weights is a bodybuilder. Given how vital muscle is, it makes sense that it needs preserving. 

Factors that impact muscle loss

Several factors affect determine how quickly you lose muscle. Some are an inevitable part of life. Other factors are within your control, and you can take action to reduce muscle loss!


Muscle mass tends to peak between 20 to 30 years old. At this time, muscle-building hormone levels are at their highest. As these hormones begin to fall, muscle breakdown starts to outpace muscle building, leading to smaller, weaker muscles.

A loss of functional strength usually accompanies the loss of muscle mass. Studies reveal that muscle mass decreases approximately 3–8% per decade after the age of 30. This rate of decline is even higher after the age of 60.

Activity levels

Have you heard the saying use it or lose it? If you don’t use your muscles, your body responds by getting rid of “unwanted” muscle mass. In other words, the more sedentary you are, the faster you’ll lose muscle.

For example, if you are unlucky enough to break a leg, you’ll land in a cast or boot to allow the bone to heal. When that cast comes off, the affected leg will have shrunk considerably. You’ll have lost a lot of muscle mass in a short time.

How much muscle depends on the length of time you were immobile, but it’s quite normal to lose as much as 30% in just two weeks.

The good news is even moderate physical activity, like walking, can help reduce muscle loss. It’s not just exercise that helps maintain muscle mass, but any activity that puts healthy stress on your muscles.

Extended breaks from exercise

Exercise is vital for building and preserving muscle mass, and strength training is beneficial. Ideally, you should stick with a routine once you have begun exercising. Taking occasional breaks is okay. Consistency is the key!

While it’s impossible to say precisely how much and how fast you’ll lose muscle after stopping an exercise plan because so many factors are involved. Studies suggest that a break of 2-3 weeks is enough to cause a measurable decrease in muscle mass and strength.

The good news is that even one workout per week can help preserve existing muscle mass or at least reduce any loss to almost insignificant levels! So, while it will probably take 2-4 workouts per week for several months to increase muscle mass, just a single training session per week will help maintain your hard-won gains.


You are what you eat, and your diet can significantly impact how fast you lose muscle. Very low-calorie diets, especially when maintained for months at a time, can accelerate muscle loss.

With fewer calories available, your body looks for ways to reduce and conserve energy. One sure-fire way to do this is to decrease muscle size. Muscle tissue requires calories to maintain it. Less muscle mass means your reduced calorie intake will go further. That’s why crash diets are such a bad idea.

Your body also needs an abundance of protein from whole foods to maintain your muscle mass. Your body uses protein to repair everyday wear and tear. Consuming too little means your body won’t have the materials it needs for rebuilding. With breakdown outpacing repair, muscle loss is inevitable.


Stress is part of modern life. Stress levels can soar whether you’re at work, home, or just driving your car. Stress is often viewed as a psychological issue, but it also affects you physically and can contribute to muscle loss.

When you’re stressed, your body enters "fight or flight" mode, leading to increased heart rate, breathing rate, blood pressure, blood glucose level, and cortisol. The trouble is cortisol is a catabolic hormone, meaning it causes tissue breakdown.

If you turn back the clock to when humans were hunter-gatherers, stress was actually a good thing. It was also very short-lived. Confronted with a source of danger, stress gave you the instant energy you needed to run or fight for your life. Once the threat passed, your body returned to its pre-stress state.

However, in our modern society, we are exposed to chronic stress. This means instead of occasional bursts of cortisol, levels of this hormone are elevated for weeks or even months at a time. The result… accelerated muscle loss. Check out a simple technique for reducing stress here.

Negative consequences of losing muscle mass

Muscle decline from disease

Occasionally and unfortunately certain diseases can also increase the rate of muscle loss an individual experiences. We call this type of muscle decrease "muscular dystrophy".

muscular dystrophy
Muscular dystrophy

Negative consequences of losing muscle mass

Reduced strength

Less muscle usually means less strength, which can harm many aspects of your life. Even simple tasks like walking, carrying groceries, and climbing stairs are more demanding after losing muscle. The more complex these activities are, the more energy you’ll have to use to do them, and the more tired you’re likely to feel. Increased muscle mass makes life easier and less exhausting.

Unstable body weight

Muscle is metabolically active tissue, and it needs calories to sustain it. The more muscle mass you have, the more calories you’ll burn each day. If you lose muscle and don’t make changes in your nutrition habits, you may find yourself gaining weight. Conversely, adding even a tiny amount of muscle will increase your metabolism, making maintaining it considerably easier to maintain your ideal weight.

Increased risk of type 2 diabetes

Your muscles use glucose for fuel. Loss of muscle mass can increase insulin resistance, leading to a chronic increase in blood glucose levels, increasing your risk of developing type 2 diabetes.

Increased risk of injury and falls

Weak muscles increase your risk of injury. When you’re strong, picking up a heavy grocery bag or mowing your lawn shouldn’t present a real problem. But, if you’ve lost muscle, these tasks are much more challenging and could even lead to injury. A lot of acute back pain is the result of muscle weakness.

You also need muscle to stabilize your joints. Unstable joints are more likely to experience wear and tear, leading to joint injury and osteoarthritis.

A lack of muscle strength can increase your risk of suffering a fall. Falls in younger people are rarely serious but could still result in a sprain or fracture. However, when we’re older, falls are the leading cause of hip fractures and other life-changing injuries.

The more muscle mass you’ve got, the less impactful muscle loss will be as you age. That’s why it’s so important to increase your muscle mass in your 20s to 30s and work hard to maintain it after that.

Reduced quality of life

Medical science is amazing. It can help prolong your life by controlling symptoms and treating diseases that would otherwise end your life. However, if you’ve lost so much muscle mass that you’re no longer able to walk unaided, get out of bed, or even sit up, life probably won’t be a whole lot of fun. If you want to live an independent life as you get older, minimizing muscle loss is a must.

Decreased longevity

The more muscle you have as you age, the longer you’ll probably live. While some age-related muscle loss is unavoidable, muscle loss can be significantly reduced so that it has less of an effect. Muscle appears to be the armor that can help you live longer.

Grip strength, a common test used to estimate muscle mass, is a reliable indicator of increased live span. The theory is that if you’ve got strong hands, the rest of your body is probably strong too.

Ways to minimize muscle loss

It’s beyond the scope of this article to provide you with a detailed blueprint for minimizing muscle loss. However, we CAN give you an idea of the types of things you need to do to keep muscle loss to a minimum.

Strength training 

Lifting weights is the best form of exercise for building and maintaining muscle mass. Bodyweight exercises can be similarly beneficial.


The occasional 1 to 2-week break from exercise won’t do you any significant harm, and the extra recovery may even be beneficial. However, you can’t store fitness indefinitely, and your workouts must be consistent to maintain your muscle mass.

Consume adequate protein 

According to the Mayo Clinic, “the recommended daily amount of protein is 0.8 grams per kilo of bodyweight” if you don’t exercise much. However, if you exercise regularly and want to prevent muscle loss, you’re looking at 1.2 grams per kilo.

Quit smoking 

Chronic smoking increases muscle atrophy. Quitting smoking will help maintain existing muscle mass and make strength training workouts more effective.

Reduce your alcohol intake 

Drinking too much booze can lead to weaker, smaller muscles and a condition called alcoholic myopathy. The symptoms include muscle stiffness, spasms, muscle loss, and cramps. While the occasional alcoholic drink probably won’t do you any harm, binge and chronic drinking invariably will.

Keep moving forward

While you probably won’t be able to avoid muscle loss altogether, there are plenty of things you can do to preserve your muscle mass and make any potential loss less impactful.

Regular strength training will invariably help, as will eating healthily and consuming plenty of protein. Reducing your stress levels, not smoking, and drinking alcohol in moderation, if at all, will also be beneficial. 

If you’re not sure where to start with strength training or could use some guidance on healthy eating, trainwell (formerly CoPilot) is a great affordable option that provides you with an expert 1-on-1 remote trainer. Get all the benefits of in-person coaching with the convenience and flexibility of a remote fitness trainer. Plus, you’ll get support in between sessions for no extra charge. That’s pretty sweet. 

Try trainwell for free and start investing in the future of your muscle strength. 

Written by Patrick D.

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