There is a lot of controversy about whether aerobic exercise, particularly steady-state cardio and long-distance running, can cause muscle loss. The basic claim is that long periods of aerobic exercise leads to burning muscle for energy.  

This idea is supported by the fact that aerobic exercise places a greater demand on the body's energy stores than resistance or anaerobic training, which means that muscle can be broken down to meet this energy demand. 

So does cardio burn muscle? Today we're going to break down cardio and how it affects an individual's muscle growth. 

Yes, cardio can burn muscle mass... Not the answer you were looking for, huh?

However, don't fear. While the above statement can be true, I need to make one thing clear: This will only happen if you're not performing enough weight training OR you're not eating enough calories and protein (needed to sustain your muscle mass).

Initially, cardio will burn fat first, but if you're dieting and are currently in a calorie-deficit, there's a higher chance that the weight you're losing will include muscle mass.

Which is the opposite of what you want, especially if you're looking to maintain as much muscle as you can during your dieting. 

That's why it's crucial to try to keep your protein intake up during your weight-loss journey. 

If you get your dieting on point, there is no reason why you can't use it as a tool to lose body fat while improving your cardiovascular health.  

By improving your cardiovascular health you'll have a better capacity to do the things you need to do to build muscle, such as Anaerobic exercise "aka" strength training or weightlifting.

Below you'll discover some of my top tips so you can effortlessly incorporate cardio in your workouts without sacrificing your gains.

Doing Cardio At The Wrong Time 

Cardio is important and should be a part of everyone's fitness routine. However, there's a time and a place for cardio. If you're trying to lose weight, you should do your cardio in the morning because your body will be more sensitive to insulin. 

Insulin is a hormone that tells your body to store fat, and it's also one of the hormones that spike when you eat a meal. When you're in a fasted state, your insulin levels are low, and your body starts to burn fat for energy. 

Most fitness experts will tell you to schedule cardio after weight training because your body needs the energy from the workout for more strenuous activities.

Therefore, doing cardio before weight training will exhaust the body before it gets to properly work out and build muscle. 

Doing The Wrong Type Of Cardio 

Don't do long, slow cardio sessions if you're trying to build muscle. Cardio is very important for general health and conditioning, but if your goal is to build muscle, you need to be doing cardio that is high in intensity. 

High-intensity interval training (HIIT) is one of the best ways to burn fat. It increases the afterburn effect, so you continue to burn calories even after your workout is over. It also increases your metabolism and helps you build muscle faster. 

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Doing Too Much Cardio 

Doing too much cardio when you're trying to build muscle can have a negative effect on your muscle growth. When you're doing cardio, you're breaking down muscle tissue because your body is using energy to fuel your workout. 

Stick to short, intense cardio workouts. 

a person training with battle ropes

7 Main Benefits Of Cardio Workouts

Cardiovascular workouts are one of the best ways to lose weight and get fit. Cardio workouts improve endurance, tone muscles, and burn calories.  

Check out some of the best reasons to fit in a cardio workout: 

1. Great For Weight Loss 

Cardio is a great way to lose weight. While lifting weights will help to build muscle, cardio is the best way to burn fat.

Cardio exercises like running, cycling, and swimming are all great ways to burn fat and lose weight.

2. Strengthens Your Heart 

Cardiovascular exercise refers to any type of exercise that raises your heart rate and keeps it elevated.

It's often referred to as aerobic exercise. By strengthening your heart through cardio, you'll also be reducing your risk of developing high blood pressure and high cholesterol. 

3. Reduces The Risk Of Several Diseases 

Cardio training helps to reduce the risk of developing heart disease, high blood pressure, stroke, metabolic syndrome, Type 2 diabetes, and certain forms of cancer. 

4. Improves Lung Capacity 

One of the main benefits of cardio is that it increases your lung capacity. This can be particularly helpful for those who are asthmatic because it can help you breathe more easily. 

5. Naturally Boost Your Energy 

Cardio is one of the best ways to boost your energy levels and to improve your mood. Cardio helps to release endorphins, which are hormones that are responsible for making you feel happier. 

6. Great For Mental Health 

If you're feeling stressed, anxious, or depressed, cardio can help. "Exercise is not only good for the body: it can transform your mind too," says John J. Ratey, Ph.D., an associate clinical professor of psychiatry at Harvard Medical School in his book "Spark." 

7. Better Sleep 

Cardio exercise helps you sleep more soundly. A study from the University of Georgia found that subjects who exercised before bed reported better quality of sleep than those who didn't exercise [1].

Researchers believe that exercise helped the subjects sleep better by lowering levels of the stress hormone cortisol, which can interfere with sleep. 

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woman stretching her arms in the morning in bed

How To Do Cardio Without Losing Muscle? (6 Tips From A Bodybuilder)

1. Light Bicycling 

Shorter, high-intensity workouts are great for conserving muscle mass, decreasing body fat, and building aerobic capacity — things cyclists should always be striving to improve. 

2. Walking

The human body is designed to be very good at storing energy, which means that muscle breakdown from walking occurs only in extreme situations.

In fact, the body has a network of stored fuels that can last for days without additional intake. Therefore, walking relatively short distances is unlikely to cause any muscle loss.

3. Conditioning

Conditioning workouts are designed to be short and intense, lasting no more than 20 minutes. These workouts are designed to improve your capacity to work at a higher intensity for a longer period of time. 

If you want to get leaner, building lean muscle mass is the key. This is where conditioning workouts come in. These workouts don't just help you lose weight, but they help you burn more calories overall, which helps you lose weight faster. 

4. Eating Well 

Regular consumption of small meals (5 or 6) throughout the day can also keep your metabolic furnace burning while discouraging lean mass loss. 

5. Swimming

Swimming is one of the best ways to build muscle [2]. It's not only heart-healthy but also burns calories and builds muscle size in a more effective way than running and biking, as it utilizes gravity and water for resistance. 

Water is up to 1,000 times denser than air, so swimming is equivalent to exercising against a greater force than you would experience on land. 

6. Light Elliptical 

One of the many benefits of elliptical machines is that they engage nearly every muscle in your body. In fact, a twenty-minute workout on an elliptical trainer can burn up to 400 calories - and it helps to avoid imbalances. So you'll be maximizing your muscle-building potential with every stride you take. 

Related Article - Best Affordable Ellipticals

People Also Ask (FAQs)

Will 30 minutes of cardio burn muscle? 

In short, no, 30 minutes of cardio won't burn any of your hard-earned muscle tissue. Cardio does not directly burn muscle tissue like fat tissue. It will not "break down" muscle tissue. That's not how the body works. It will break down fat and use it for fuel. 

Will running burn muscle? 

While it's a common idea that running will burn muscle, it's actually not true. Running will not burn muscle. However, you will burn a lot of calories, which may also be detrimental to your muscle mass if you're not eating enough. 

How can you tell if you're losing fat or muscle? 

The main way to tell if you're losing fat or muscle is to check your body fat percentage. If you're losing body fat but not weight, it means that the fat is coming off your body, but the muscle is staying put. 


f course, you can build muscle while doing cardio – the key is to ensure that you are not doing too much. If you overload your body with training and don't give it time to recover, then you're going to lose muscle tissue, not gain it.  

Try to mix up your training so that you hit all of your muscle groups – we recommend doing two to three cardio days per week. 




Lee Kirwin

Lee Kirwin

Lee has worked in the fitness industry for over 15 years. He's trained hundreds of clients and knows his way around the gym, including what you need for your garage gym. When he's not testing products, he loves weightlifting, Ju Jitsu, writing, and gaming.