How Much Cardio Is Too Much? Signs, Risks, and Best Practices

Time to Read: 10 minutes

Losing weight and burning calories are popular goals when starting cardio routines. Jogging and biking burn many more calories than other types of exercise and condition the heart and the lungs. However, there can be too much of a good thing when it comes to cardio. Although cardio in moderation is good for the body, too much can have a negative effect.

How much cardio is too much, and how much should cardio should you do?

First and foremost, everybody should regularly perform cardiovascular exercise to maintain a healthy heart and lungs. 

According to the Physical Activity Guidelines put out by the U.S. Department of Health and Human Services, all adults should get 150 minutes of physical activity a week of moderate-intensity. This can be spread out to 30 minutes five days a week. The sessions do not have to be continuous but can be in ten or 15-minute spurts of activity. According to the article, people can do twice as much or 300 minutes per week and still reap health benefits. 

So How Much Cardio Is Too Much? 

As you start to go beyond 300 minutes per week (this is 1 hour, five days a week), you’re at increased risk of too much cardio. The exact amount will vary from person to person based on the intensity of your sessions and your own physical fitness.

Risks of Doing Too Much Cardio

Many people have to motivate themselves to fulfill the 150 minimum, but it is possible to do too much. 

Excessive exercise can have the same negative effect on the heart as a sedentary lifestyle. High doses of exercise can be linked to atrial fibrillation, malignant ventricular arrhythmias, and coronary artery disease. In addition, constant exercise can lead to a multitude of injuries, such as shin splints, knee problems, and sore joints.

Although many people decide to do cardio in the first place to burn fat, excessive cardio can actually convince the body it is in starvation mode and can cause it to lose muscle. As a rule of thumb, unless someone is a long-distance runner or training for a marathon, more than one hour of cardio a day can be counterproductive.

A marathon or a triathlon can be a crowning achievement, but if training for such races becomes a constant routine, cardiac problems could arise. 

According to a study by the Mayo Clinic, training for these events can cause an enlarged heart and affect the right ventricle. The heart and arteries return to their original size after a week following the long race, but if there isn’t sufficient time to give the heart rest between these kinds of events, myocardial fibrosis and arrhythmias could develop.

Signs That You Are Doing Too Much Cardio

hurt runner

You Feel Sore All the Time

When you are resting after a workout, your body isn’t simply doing nothing. During rest periods, our body repairs itself, and muscle tissue rebuilds itself to become stronger than it was before. 

People who do too much cardio do not allow their bodies to rest sufficiently and may lose the many potential benefits provided by their exercise routine. Even the most avid cardio fan should take at least one day off a week to let the body repair itself. Fitness expert John Gaglione told Shape magazine, “The more fit and stronger you become, the more recovery you need.”

In addition, the more exercise you do, the more likely you are to get injured or wear out your joints. This is particularly true of high impact exercises such as jogging, squash, or aerobics. If your feet are constantly hitting the ground, your joints and knees are likely to suffer. Taking a rest now and again or varying routine can correct this strain.

You Lose Muscle Mass

Many people make the assumption that cardio is a super calorie-burning exercise that can lead to a high level of fat loss. Although running, swimming, and biking can burn a large number of calories, it may not affect your metabolism as much as you may think. 

After we complete an exercise session, metabolism can return to its former resting rate. In addition, the rate of calorie burn may be high, but as fitness trainer Dave Smith explains in the Huffington Post, cardio doesn’t distinguish between fat loss and muscle loss

Not only does the concept of muscle loss seem counterproductive to the whole notion of fitness, but losing muscle can actually slow your metabolism while at rest. Gaining muscle helps you burn calories from fat more efficiently, but if you are shedding muscle as well as fat, you will lose these benefits.

Your Body Is Not Getting Firmer

You may be spending over an hour a day doing cardio, but your body may seem like merely a smaller version of what it was before. You feel disappointed that you still have that belly flab, and your body doesn’t have the definition you expected when you began working out every day.

If your focus for cardio is calories burned and not physical and health benefits, you may not achieve the muscle tone and definition needed to improve your curves, flatten your tummy, and accentuate your figure.

You Feel Tired

Moderate exercise can create an energy boost. A 20 to 30-minute jog or a few laps in the pool can make you feel more alert and release endorphins that can lift your mood and energy level. 

However, hours and hours of cardio day in and day out can have the opposite effect. You may feel tired constantly and feel down. You may want to take a nap at work or doze off during an important meeting. This constant tiredness is due to the stress you are putting your body through with excessive cardio exercise. 

A little to moderate exercise can relieve stress and create an outlet for the tension you may be holding in your body. However, too much exercise can put your body through too much stress. When we are undergoing too much stress from exercise, it can be difficult to have enough energy for day to day activities.

Inability to Sleep

can't sleep

You may feel tired all day as the result of too much cardio, and yet it may be impossible for you to fall asleep and stay asleep at night. What gives?!

If you suffer from insomnia, your doctor may recommend an exercise routine. Getting some energy and stress out of your system may be a great prelude to a good night’s sleep. However, excessive cardio exercise can release cortisol into your system which can interfere with sleep. According to a study published in the National Library of Medicine, people who participated in strenuous exercise released higher levels of cortisol, a stress hormone that can interfere with sleep, than those who engaged in low to moderate exercise. 

You No Longer Enjoy Working Out

Most people need a little motivation from time to time to stick to a workout routine. However, if you find that you are stuck in a rut and even dread working out, your body and mood may be telling you it is time to diversify beyond just cardio. One way to destroy your exercise routine is through burnout. 

Pushing yourself too hard to the point where you don’t feel good doing cardio anymore will ultimately be counterproductive. Cutting down on the amount of cardio you do every week, diversifying, or taking a break may be essential if you want to reach your long-term goals.

Running Multiple Marathons

Running a marathon should be a milestone you can be proud of. However, it is not a good idea to do one marathon after another. If you are training for yet another marathon shortly after you have finished the last one, you may be overdoing it on cardiovascular exercise. If you don’t space out plenty of rest time between marathons, you may be harming your heart. Marathoners and triathletes may experience heart enlargement while training for their extremely long races. Even though the heart does go back to normal size after a race, training for multiple marathons and triathlons a year can harm your heart.

You Are Doing More Than an Hour a Day

Unless you are in the middle of training for a marathon (and hopefully you aren’t running one marathon after another), more than an hour a day every day may be too much cardio. 

A number of fitness experts say that not only is it not necessarily better, but over an hour is counterproductive. Simply reducing the sessions to 45 minutes or taking a day off may be enough to create a more moderate exercise routine. It may be fine to exercise more than an hour every day if you are a dedicated gym rat as long as that hour doesn’t entirely consist of cardio exercise. 

Feeling Out of Sorts

In addition to the above symptoms, you may just be feeling like things aren’t quite right. Not only do you have difficulty sleeping, and feel tired all the time, but you could also feel moody and be more likely to come down with respiratory problems or colds. Excessive cardio exercises give the body the impression that it is facing a major, ongoing threat. In response, the body releases cortisol, a stress hormone.

Elevated cortisol has a host of negative symptoms, such as weight gain, high blood pressure, moodiness, insomnia, and a compromised immune system. Putting your body under the stress caused by an excessive amount of cardio may create problems that outweigh the benefits, particularly if your body is releasing high levels of cortisol

Alternative Exercise Routines

weight lifting

If you think you are doing too much cardio, there is no need to give it up completely. You may want to simply reduce the amount of cardio you do or to focus on working your cardiovascular system differently. In addition, there are other types of exercises you may have been neglecting for the sake of focusing almost entirely on cardio.


High-Intensity Interval Training is cardio, but it isn’t like going for a long-distance jog or an hour-long swim. It may be a great alternative cardio routine if you feel burned out with your regular routine. The HIIT routines require short bursts of intensive effort during intervals. Fitness trainer Bob Sulaver told Self magazine that the high intensity required by HIIT workouts burns fat rather than just calories. This lessens the muscle loss that can occur during many longer, low-intensity cardio workouts that are aimed at general calorie burning.

In addition, many HIIT workouts add a strength training element that is ignored by long-winded cardio workouts. You will find many HIIT routines incorporating push-ups, barbells, and kettlebells for muscle conditioning. These workouts combine the best of strength and endurance workouts in one session, which can often be under 30 minutes. HIIT workouts have among the most efficient afterburn rates, the rate the body burns calories after the workout is over.

This makes HIIT workouts a great investment of your time and energy.

Strength Training

Just as everyone should eat a balanced diet, having a balanced exercise routine can help improve your overall fitness. Strength training is an ideal complement to cardio. The cardio will help you burn calories rapidly and work your heart and lungs. Strength training will prevent you from losing muscle as you lose weight, give you more confidence and energy, and tone and shape your body.

Strength training, such as weight training and bodyweight exercises, can improve your fat to muscle and increase your afterburn potential, the number of calories you burn while at rest. If you strengthen your muscles, you may be less vulnerable to injuries after a long run or a day at the tennis court. In addition, strength training can lessen the stress on your body caused by repeated cardio workouts. 


Yoga can counteract many of the negatives caused by doing too much cardio and can complement your regular cardio routine. Yoga does many things that your regular jogging and swimming routine may not and can give your greater strength and flexibility to prevent injury during your next road run. The focus on breathing required in yoga leads to a feeling of relaxation and can counteract many of the stressors placed on the body by strenuous cardio routines and everyday life.

According to the National Library of Medicine, yoga was found to be as effective or more effective in improving a number of health-related outcomes. Yoga is particularly efficient in regulating the hypothalamic, pituitary, adrenal axis, and the sympathetic nervous system. Also, poses and slow movements in yoga are low-impact and do not have the same potential for injury as many kinds of sports or running.

How Much Cardio Is Too Much – Next Steps

The exact answer to how much cardio is too much will vary from person to person, but there is a limit for everybody. That tends to start around 300 minutes of moderate-intensity cardio per week. Your number will be above or below this, but it’s a good starting point. First and foremost, pay attention to your body. Your body will give you signs when you’re doing too much.

Creating a balanced exercise routine is the key to general fitness. Complementing a cardio routine with strength training and yoga can increase flexibility and strength as well as endurance. While cardio has many benefits, diversifying your exercise routine will give you the best overall results.