Q&A: How much cardio is too much?
Thursday, November 24, 2011
LifeTime WeightLoss in Exercise, Tom Nikkola, cardio, endurance training


I want to start off by saying how much I enjoy reading all of the useful feedback and tips you provide Life Time readers!! Are there upper limits on how much cardio one should do when combined with a strength training program? Perhaps I could see it in a post at some point? 



Very good question Staci! Cardio is good for us isn’t it? If some is good, isn’t more even better? Like most other things, that’s not the case. There is a point of diminishing returns when it comes to how much time is spent doing cardiovascular exercise. In fact, there is evidence long-duration exercise such as running a marathon even leads to heart damage.[i] What’s interesting is marathon runners tend to have better than average lipid profiles, yet they still displayed higher rates of heart damage. The realization of the possible effects of vigorous endurance training is fairly new. So, doing too much cardio isn’t good, but at what point is too much?

There is not a clear-cut answer to how much is too much for everyone. Some people can handle larger volumes of exercise for certain period of time, but just because they can handle it does not mean it’s ideal. The amount of cardio (or strength training) you can handle depends on how quickly your body can recover from one workout to the next. Your recovery is enhanced through proper nutrition, like vegetable, fruit and protein consumption, the use of nutritional supplements, proper hydration, sleep, and stress management. If these factors are not dealt with, the volume of exercise an individual can handle is greatly reduced.

Assuming nutrition, sleep and stress management are taken care of, an hour of total exercise is probably sufficient for general health and weight management goals. Some people may prefer to do a little more, or their trainer may have them exercising more if they're on a more aggressive weight loss plan. The key is to pay attention to what your body is telling you. The following are five ways you can identify if you're exceeding your body's ability to recover from workouts. If you notice any of the following, it could be a sign to reduce your exercise volume. Remember, though, recovery also requires proper nutrition, rest, hydration, stress management and appropriate supplementation. You can reduce the symptoms of overtraining below through any of these means.   

1. Elevated resting heart rate

When you wake in the morning, grab a stopwatch from your nightstand and check your pulse for 60 seconds. As long as you don’t wake up to a noisy alarm that shocks you into alterness, you should get an accurate reading. Jot down your resting heart rate each morning. If you notice a day or two where it’s elevated, it could be due to poor sleep or a little anxiety when you wake up. If you notice a trend, where it’s gradually rising each week, it could be a sign of overtraining. Interestingly, if you don’t back off and become severely overtrained, your resting heart rate could actually start falling well below normal as your metabolism starts slowing down.

2. Feeling flat during strength training

“Flat” muscles or slower reflexes during your workouts are another sign you’ve been overdoing exercise. Getting to the point of overtraining syndrome takes weeks, but even over a couple workouts, you can wear down your recovery abilities. Let’s say Monday your workout includes squats, lunges and a few sets of some kind of hops or jumps. You might have some other exercises mixed in as well. You then hop on an elliptical for some cardio. The next day you decide to run on the treadmill, overlooking the fact your legs aren’t recovered yet. By Wednesday or Thursday, you just don’t feel like you can put forth the effort you know you should. Your muscles don’t respond or you feel fatigued before the end of your set. The muscles in your legs need to recover, but so does your nervous system.

If you’re not providing the right kind of nutrients to aid in recover, like protein, vitamins, minerals and water, you won’t have the building blocks for repair. But beyond that, you need to give your body enough time to repair itself. As you get in better shape, you may find you can recover faster, but each individual will recover at different rates. If you have a friend who did the same workout and seems to be ready to go, don’t blame yourself if you don’t feel as recovered as he or she does. Pay attention to your body. Sometimes if you’re “just not feeling it” when your workout gets started, it can be a sign it’s time to back off.

3. Growing aches and pains

New aches and pains are another sign you should back off and let your body heal itself. The most common example is a stress fracture. However, muscle aches that don’t go away, or shoulder, hip, knee and ankle pains that progressively get worse are signs your body isn’t getting enough time to recover. It could also be a sign you’re not using proper technique, or in the case of running, your gait or stride might need some improvement. If you wake up in the morning and something doesn’t feel right when you try to move, it could be time to reduce the duration or intensity of your cardio. You could also replace your planned workout with an active recovery day. Go for a light walk or bike ride, or even better, try a yoga class.

4. Elevated heart rate during exercise

The average person does not have the intuition to know when he or she is under-recovered the way an experienced athlete might. That’s where a little technology can be a great guide. Your heart rate during your workout can be a sign you’re not recovered is during an actual workout. Let’s say Staci likes to run for some of her cardio workouts. We’ll say her target heart rate range is between 140-150 beats per minute for her workout. She’s built up her conditioning to the point where she can run at 7 mph while staying within her target heart rate range. If she is not recovered, she may find she has to keep her speed at only 6.0 mph to stay in her 140-150 beats per minute heart rate range.

If you log your workouts in a notebook, and make note of your average heart rate, speed and other variables, you’ll notice you can’t maintain the same intensity at the same heart rate if you are over-trained or under-recovered.

5. Disrupted sleep patterns

Another sign of under-recovery or overtraining is disrupted sleep. An inability to fall asleep or stay asleep, or even the in ability to fall into deep sleep can all be signs of overtraining. Disrupted sleep can also be a result of emotional stress so before pointing the finger at an exercise program, it’s important to look at your whole lifestyle as well as your nutrition program. Sleep problem can lead to a downward spiral as it relates to exercise. Deep sleep is the level of sleep most important for exercise recovery. This is the state of sleep where the body repairs and regenerates. If an individual lacks sufficient deep sleep, it can lead to poor exercise recovery. The poor recovery adds more stress to the body which can further disrupt sleep. That’s why it so important to go to bed at the same time each night and get at least 7-8 hours of quality sleep.


Understanding when you get to the point of “too much” requires a good understanding of how your body functions. The five signs above are indicators you may be overtraining or under-recovering. Remember, you can handle more exercise when you follow an appropriate nutrition program and get sufficient sleep. Other stresses can also impact how much exercise you can tolerate. Remember, exercise is just a stimulus to get your body to change. Doing more once you’ve created the stimulus to adapt and become stronger, faster and healthier doesn’t mean you’ll produce better results. In fact, too much can be worse than not enough. Your body is pretty smart. Listen to what it tells you.

Keep the conversation going in the comments section. 

If you have a question you'd like addressed in a future article, you can post your question below, or email it to tnikkola@lifetimefitness.com

This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.

[i] Mohlenkamp S, Lehmann N, Brueckmann F. Running: the risk of coronary events. Prevalence and prognostic relevance of coronary atherosclerosis in marathon runners. Eur Heart J. 2008;29(15):1903-1910

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