Does Running Make You Lose Muscle? – 5 Easy Tips To Avoid

One of the most prominent features of any seasoned runner is the slim body they possess. It is a common belief that running causes you to lose muscle mass. If bodybuilding is one of your goals, losing leg muscle is not something you want to happen to you. The question then is, does running make you lose muscle? Or is this a little misconception?


Understanding The Facts

Low Fat Percentage

One of the first things you need to understand is that we cannot dictate that our bodies only burn fat and keep our muscle. What your body chooses to burn depends on what is available. If you have no fat available as an energy source, your body will be forced to burn muscle instead. (1)

For males, 3-5% body fat is considered dangerous and if your body is in this situation, running will definitely result in muscle loss.(2)

Low Protein Intake

Another factor to consider is the importance of protein in your diet. Protein is composed of amino acids which are responsible for building and repairing muscle tissue. (3)

If you do not consume enough protein daily, your body is in a catabolic state in which it burns muscle for fuel. Running in this state forces your body to target your muscles. On the other hand, with enough protein consumption, your body is in an anabolic state which allows for complete muscle recovery. (4)

The two important points you should take away from these facts are:

  • Low Fat Percentage + Running = Muscle Loss
  • ​Low Protein Intake + Running = Muscle Loss

How To Avoid Muscle Loss

#1. Eat Enough Protein Everyday


The first key to being able to run without worrying about muscle loss is to eat enough protein. Protein is considered to be a macronutrient which means your body needs big amounts of it to survive. Interestingly, your body is not able to store protein so you need to regularly provide it. (5)

The amino acid called leucine is what has been shown to help preserve body muscle. It is one of the amino acids that our bodies cannot produce. Studies show that eating foods with this amino acid helps promote muscle synthesis. (6)

Some of the best sources of protein include (7) raw milk, eggs, whey protein, black beans, yogurt, lentils, and chicken.

According to researchers, athletes or active individuals require more protein than normal individuals. For athletes, it is recommended that 1.8 - 2.0 g of protein/kg of body weight is consumed per day. (8) This is twice the amount for regular individuals.

Protein is especially important after exercise since, during physical activity, muscle tissue is damaged. Make sure that you take a high protein meal to help your muscles recover.

On the topic of eating well, also always give your body enough hydration before, during and after your runs. Increase your water intake on sunny days especially since you are running outdoors.

Whenever your body is dehydrated, it will cause you have low blood volume.

With a low blood volume, your body will struggle to transport enough oxygen to your cells which can cause the common side stitches.​

#2. Keep Up With Strength Training


Studies show that inactive adults experience 3 to 8% muscle loss every ten years. (9) Doing strength training can help conserve and enhance muscle mass that may diminish by age. (10) For runners, strength training is more valuable.

In a study conducted, runners and cyclists were put on the resistance-training program for 10 weeks. At the end of the trials, a 30% increase in leg strength was observed and a 13% increase in quick bouts of running. (11)

Another study compared the effects of using own body weight for strength training versus no strength training at all. It was found that the group who had performed half squats three times weekly for two months had improved maximal aerobic speed by 21.3% (12)

Clearly, strength training exercises can not only help you prevent muscle loss but can help you run faster, longer and stronger.

#3. Increase Calorie Intake On Training Days


As we have mentioned, one of the reasons that your body turns to burning muscle instead of fat is because there is no fat readily available. One solution is what is called calorie cycling. Calorie cycling or shifting is alternating between high and low-calorie periods depending on your training. Ideally, you consume more calories on the days you have heavy training and less on recovery days. (13, 14)

According to research, the benefits of calorie cycling include less hunger and ability to stick to a diet. In addition to this, by providing your body with enough calories on training days, you give it the energy it needs to prevent it from turning to muscle.

#4. Find A Balance


Aside from doing the right training and eating protein, there are a few things that you should avoid to prevent muscle loss when running.

1. Overtraining

In one study conducted on athletes in the trans-Europe run that involved running 2,800 miles in 64 days which would average 43 miles daily, interesting results were discovered. Although no muscle loss was observed in their upper bodies, their leg muscles experienced muscle loss. (15) The reason? Overtraining.

The lesson is simple: do not over train. Inasmuch as you want to improve your running performance, training for too long will backfire and cause you to lose muscle mass which in turn will hinder your performance.

2. Short Term Fatigue

Another habit that can contribute to your losing muscle mass is short-term fatigue. For example, if you play an intense game of basketball and then do some strength training, you will be too tired to maintain proper form.

The importance of maintaining proper form is that without it, your strength training will give little or no results. Without proper form, you won’t’ be able to develop muscle. (16)

It is best to focus on your training before engaging in other sports. This way, your muscles will be at their full range of motion and able to perform your workout routine with the right form.

3. Repetitive Motion Injury

This is triggered when a group of muscles is overused and can cause loss of strength. (17) If you do any kind of cardio exercise for extremely long periods of time, you are putting yourself at risk of repetitive motion injuries. When your joints or muscles are in pain, they are less likely to gain muscle. The saying “no pain, no gain” should not be taken too literally.

#5. Increase Omega 3 Fatty Acids Intake


There have been numerous studies conducted to analyses the connection between supplementing with Omega 3 Fatty acids and prevention of muscle loss. These nutrients have been found to help preserve muscle mass and also have anti-inflammatory qualities which are valuable in helping with muscle recovery. (18)

For example, in one study conducted in 2011 to evaluate the effect of in taking Omega 3 Fatty acids on muscle decrease found that there was an increase of muscle protein synthesis in adults. (19)

In another study, fish oil derived from Omega 3 fatty acids caused a decline in the rate of muscle loss in adults. (20)

You can find Omega 3 Fatty acids in flaxseed oil or fish oil. Foods such as sardines, bluefish, salmon, tuna, and trout are rich in omega 3 fatty acids. In addition, walnuts, flax seeds, soybean oil, and canola oil also have this vital vitamin.


So does running make you lose muscle? The answer is it depends. Running can cause muscle loss if you fail to eat enough protein and do strength exercises. On the other hand, if you keep up with your protein intake, do the right strength exercises and practice calorie cycling, running can help burn fat, not muscle. The secret lies in conditioning your body so that it burns fat, not muscle.

In addition, avoid habits that may trigger muscle loss such as short-term fatigue, repetitive motion injury and overtrain. If you follow these steps, running will be your ally in muscle gain, not your enemy.

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