How Long Does it Take to Lose Muscle?

How Long Does it Take to Lose Muscle?

Let’s say you work out on a regular basis and have a good amount of muscle, but you are about to take an extended vacation. Can you lose any muscle during the few weeks that you will be gone?

This is a very common question that even I’ve asked myself a time or two throughout the years. When you work hard for something, you definitely don’t want to lose it for no reason.

Muscle loss is a common concern for many gym goers when they will be out of the gym for whatever reason. I don’t blame them.

Whether it’s due to an illness, injury, or lack of motivation ... not working out will result in muscle loss over time. Trust me, I know from personal experience, and it wasn’t fun.

Fortunately, there are ways to prevent muscle loss and maintain your strength levels. You just have to be willing to change things up a bit sometimes.

There are several factors to be aware of when looking at muscle loss. This includes nutrition, types of exercises, amount of rest, and even your age.

Let’s talk more about how long it takes to lose muscle, and how to regain it after a period of inactivity.

How Long Does It Take to Lose Muscle?

The exact answer depends on your current fitness level and how long you are inactive. So really, it depends.

The more muscle you have, the harder it is to maintain, and the more likely you are to notice any decreases in size.

Muscle tissue burns a lot of calories, and the body doesn’t want to burn through a lot of stored calories for no reason. So, if you don’t show your body why you need that muscle with exercise, you’ll definitely lose some of it over time.

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On average, people notice some muscle loss within a few weeks when they stop exercising. Although it won’t go down a crazy amount in that time frame.

Some studies show that within the first 2 weeks of not training, you may lose 5-10% of the muscle mass in certain areas [1]. Most people think they’re losing a ton of muscle fiber size in the first couple weeks, but that doesn’t seem to be the case.

The initial decrease in muscle size isn't what you'd think. It's actually a loss of carbohydrates and fluid that is stored in the muscle.

So don’t be too alarmed if you notice smaller muscles.

Even if you have to take a break from training for whatever reason, it takes time to see a big decrease in strength and muscle fiber size.

It's also a lot easier to regain muscle you’ve lost than it is to build brand new muscle, so losing muscle is hardly something you cannot come back from.

What Does It Mean to Lose Muscle?

When people refer to losing muscle, they most often refer to two things:

Muscle size - either by looks, or seeing their body weight go down.

Muscle strength - their ability to lift the same heavy weights, or complete the same amount of reps.

As with anything else, use it or lose it. On the bright side though, you might maintain strength a little longer than you’ll maintain muscle [2].

Sure, losing carbs and fluid from the muscle results in your muscles looking and feeling smaller ... but the loss of actual muscle mass is much slower.

With that being said, you will lose muscle mass much faster if you stop training altogether. Because of this, I always recommend finding a way to train when you can.

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Even if an injury or vacation prevents you from training as often, it's not the end of the world. If you can at least get in some form of bodyweight training, you’ll hold on to much more muscle over time.

Keep your protein intake high and you’ll maintain even more. That's because your muscles need protein to grow and maintain their size.

By consuming a lot of protein, even when you're not training as often, you'll preserve much more muscle mass.

Does Age Play a Role in Muscle Loss?

One thing to keep in mind if you are taking a break from training is your age. Your age will impact your ability to maintain muscle size and strength the older you get.

Muscle mass typically peaks at age 30, and begins a steady decline thereafter. So, if you are over the age of 30, there's a good chance you will naturally lose more muscle mass than your younger counterparts.

You can expect to lose 3-5% of your muscle mass each decade after age 30, in addition to any declines due to inactivity [3].

If you are concerned about maintaining the strength and size of your muscles, you're not alone. To do this, you will want to be diligent about regular weight training and keeping your protein intake up.

Even when you can't work out as much as you'd like, this will help you maintain as much muscle as you can.

Don’t get too caught up in chasing numbers in the gym. Instead, focus on consistency and proper form so you can keep training without injury.

How to Regain and Maintain Muscle Mass

There are plenty of situations that will mean a decrease in physical activity levels. That could cause you to lose muscle if you aren't careful.

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There are also plenty of ways to maintain your muscle even when your activity levels drop. Consider the following tips to help you maintain muscle mass and muscle strength.

Keep moving. If you can’t hit the gym like you usually would, you can still maintain muscle mass by training when you can. Even simple bodyweight exercises are better than just sitting on the couch.

Visualize lifting heavy weights. I know this might sound weird, but visualizing heavy workouts can still get you results. For example, those with ACL injuries who visualized lifting heavy weights during their recovery maintained more muscle and strength than those who didn’t [4].

The brain can't always tell the difference between thought and reality. Your mind is more powerful than you think!

Maintain your calories. You will need to adjust your calorie intake based on the decrease in activity level. You still need to be sure not to go too low in calories in order to maintain your muscle mass.

Any calorie deficit will result in weight loss and a more rapid decline in muscle size.

**If you need help figuring out how many calories you need for your specific fitness goal, check out the 1st Phorm App here!

Download the 1st Phorm App

Maintain your protein intake. As you focus on maintaining your calories, be sure to get plenty of protein in your diet too. Your body needs protein to build and maintain muscle mass.

Therefore, eating food that is high in protein will give you the building blocks you need to maintain that muscle. A good rule of thumb is 1 gram of protein per pound of your goal body weight.

Remember, you will regain muscle quicker than it originally took to build it, so you can increase muscle strength and size pretty soon after you begin training again.

It still takes time, but it’s much faster than it was to gain it the first time.

Getting Help With Your Fitness Goals

Just because you can’t hit the gym all the time does not mean that you need to stop working out. Some people do stop completely because they don’t know what it takes to maintain muscle mass when life gets in the way.

If that sounds like you, let us help!

In the 1st Phorm App, you can find a wide variety of workouts to help you with any goal. That could be to build muscle or strength, and we will even teach you how to maintain existing muscle too.

The best part is, the 1st Phorm App will set you up with an in-app advisor that also teaches you about nutrition, training, and proper supplementation. This is all part of our mission to help real people like you see real and long-term results that you can maintain!

So, whether you are fighting the loss of muscle that comes with age, or looking to build it, we can help.

Download the 1st Phorm App today to see what it’s all about and get started on your next workout!

If you have any other questions ... reach out to our NASM Certified Personal Trainers and Nutrition Coaches at HQ anytime for free!

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[1] Bodine SC. Disuse-induced muscle wasting. Int J Biochem Cell Biol. 2013 Oct;45(10):2200-8. doi: 10.1016/j.biocel.2013.06.011. Epub 2013 Jun 22. PMID: 23800384; PMCID: PMC3856924.

[2] Tzur, Adam. “The Science of Detraining: How Long You Can Take a Break from the Gym before You Lose Muscle Mass, Strength, and Endurance •.” Sci-Fit, 2 Feb. 2023,

[3] “Preserve Your Muscle Mass.” Harvard Health, 19 Feb. 2016,,risk%20of%20falls%20and%20fractures.

[4] Slimani M, Tod D, Chaabene H, Miarka B, Chamari K. Effects of Mental Imagery on Muscular Strength in Healthy and Patient Participants: A Systematic Review. J Sports Sci Med. 2016 Aug 5;15(3):434-450. PMID: 27803622; PMCID: PMC4974856.