7 Ways Exercise Can Go Wrong for Your Mind and Body

... and how to overcome each problem.

Posted Sep 27, 2014

The universal acceptance which most of us have toward exercise’s benefits may lead us to ignore its drawbacks. Ordinarily, I am first in line to sing about these benefits, particularly with regard to aging. However, there turn out to be compelling reasons to worry that exercise might not always have its desired effects. Part of this depends on exercising correctly and following the right regimen to suit your body type, age, and stamina. Even if you take proper precautions, though, you can still end up getting in trouble rather than in better shape.

This empirically-based list of exercise’s ill effects doesn’t mean you should never exercise, nor should you use these reasons to build up your argument for becoming a couch potato. Instead, read these with an eye toward learning how you can improve your ability to put exercise to work for you by following its antidote:

1. Excessive exercise is associated with tooth decay

We generally think of endurance athletes as fit in every possible way. Yet, a study of 35 triathletes compared to their non-exercising counterparts revealed much higher rates of dental cavities and other oral health problems controlling for all other factors. In a study published in the prestigious Scandinavian Journal of Medicine in Science and Sports, German dental researcher Dr. Cornelia Frese and her colleagues (2014) believe that physiological changes that occur during extreme endurance training seem to cause deleterious changes in the teeth and gums, primarily due to changes in the composition of saliva.  

You may not exercise to the extent of the elite athletes in this study, but the findings suggest that it’s a good idea to hydrate frequently while you’re exercising, which is good advice for many reasons. 

2. Exercisers use their healthy lifestyle to justify unhealthy behavior patterns

A paradoxical finding long noted in the exercise and health literature is that people who work out on a regular basis are often the same people who drink alcohol to an excessive degree. There’s some debate on this topic in psychology, but there remains strong evidence to suggest that people are capable of only so much self-control. Called the “ego depletion effect,” the idea is that any type of physical or mental exertion taxes your ability to resist temptation.  It’s also possible, that heavy-duty exercisers may feel that they deserve to drink or otherwise act in unhealthy ways, or that people who want to drink feel they need to exercise.

Either way, you need to examine the balance between unhealthy and healthy behaviors you engage in to make sure that you don’t fall into the ego depletion trap.

3. Repetitive motion can cause serious injury

People who exercise without attending to their body’s needs and limitations run the risk of developing stress-related injuries associated with overuse of the joints. Tennis players can suffer from lateral epicondylitis (“tennis elbow”), and runners can develop plantar fasciitis or patellofemoral pain syndrome (“runner’s knee”).  Subjecting a joint to the continuous movement involved in certain types of exercise can lead to problems that impede not only your ability to continue in that exercise, but to carry out your everyday activities.

To avoid repetitive motion injury, pay attention to pain before it becomes chronic, get regular checkups from a knowledgeable sports physician, and vary the type of exercises you perform.

4. Exercise can become an obsession

People can become so obsessed with exercise that they actually develop a kind of exercise bulimia.  Exercising to the point of obsession isn’t necessarily a symptom of an eating disorder. Still, the odds are that if you are an excessive exerciser, you may be at risk. One study found that women who exercise to the point of excess have increased risk of developing an eating disorder. Dutch researcher Elzbieta Kostrzwea and colleagues (2013) showed that women exercising more than 5 hours per week had eating disorder rates 2.5 those of non-exercisers.

If you find yourself exercising to the point of being unable not to, this doesn’t mean that you’ll develop an eating disorder, but you may, especially if you have other risk factors.

5. Adverse cardiovascular health effects can occur in endurance athletes

This reason not to exercise may seem completely counterintuitive to you.  Of all the reasons to exercise, reducing your risk of heart disease may seem like the most important. However, in a study of long-term endurance athletes (Patil et al., 2012), there were changes in the heart muscle that could increase the risk of developing abnormalities in the heart muscle that would compromise its ability to pump the blood in a normal rhythmic fashion. The athletes in this study weren’t your average weekend joggers—they were highly trained marathon competitors. A majority of people will benefit from endurance training, but this risk of sudden death remains an important concern.

If you’re an average runner, you’ll benefit from endurance training, but if you’re someone who regularly participates in marathons or even half-marathons, it’s important to be seen by a knowledgeable cardiac specialist.

6. Your sleep quality may be poorer when you exercise

Sleep specialists recommend that you avoid exercise close to your bedtime. The kick of adrenaline that you get from a good workout may persist for some time thereafter. However, it’s generally agreed that maintaining a steady exercise regime that ends earlier in the day helps you get better rest at night.  New evidence on young adults (Wong et al. 2013) suggests that you may get less restful sleep in general on days that you exercise. Sedentary participants who completed a bout of vigorous exercise on treadmills had less of the REM sleep associated with dreaming and more light sleep than controls who didn’t exercise at all. Exercise didn’t increase the need for sleep, but it was associated with poorer sleep quality.

On nights after you’ve exercised, it’s best to give yourself more time in bed, in order to increase the total time in which you’re in sound or deep sleep. In general, exercise should promote better sleep, but you just want to be careful to make sure you get enough of it to benefit your health.

7. Exercise guilt can make you feel miserable when you can't exercise

In contrast to exercise obsession, guilt over not exercising means that when you can't exercise, you start to blame yourself for your failings. People who stop exercising after having been reasonably active may start to feel this kind of exercise guilt to the point of becoming anxious, depressed, and ashamed. Canadian psychologist Parminder Flora and associates (2012) studied the “exercise identity” of young women.  Among women for whom exercising was a particular important component of self-definition, just thinking about relapse (stopping exercise) made them more likely to experiencet. the negative emotions of shame and guilt.

If you feel that there’s something wrong with you because you’re not exercising, it might be wise to consider just how central exercise is to your sense of who you are. It’s fine to see yourself as active and energetic, but by dominating your identity, a preoccupation with exercise can leave you ill-prepared to handle those times in life when you can’t exercise.


To sum up, each of the problems caused by exercise can be managed with the right strategy.  By seeing that exercise isn’t all good (or bad), you can incorporate activity into your lifestyle in a way that best suits your mental and physical needs. 


Follow me on Twitter @swhitbo for daily updates on psychology, health, and aging. Feel free to join my Facebook group, "Fulfillment at Any Age," to discuss today's blog, or to ask further questions about this posting.



Flora, P. K., Strachan, S. M., Brawley, L. R., & Spink, K. S. (2012). Exercise identity and attribution properties predict negative self-conscious emotions for exercise relapse. Journal Of Sport & Exercise Psychology, 34(5), 647-660.

Frese C, Frese F, Kuhlmann S, Saure D, Reljic D, Staehle HJ, Wolff D. (2014) Scandinavian Journal of Medicine and Science in Sports. doi: 10.1111/sms.12266. [Epub ahead of print]

Patil HR, O'Keefe JH, Lavie CJ, Magalski A, Vogel RA, McCullough PA (2012). Cardiovascular damage resulting from chronic excessive endurance exercise. Molecular Medicine, Jul-Aug;109, 312-21. Review.

Kostrzewa, E., Eijkemans, M. C., & Kas, M. J. (2013). The expression of excessive exercise co-segregates with the risk of developing an eating disorder in women. Psychiatry Research, 210(3), 1123-1128. doi:10.1016/j.psychres.2013.08.050

Wong, S. N., Halaki, M., & Chow, C. (2013). The effects of moderate to vigorous aerobic exercise on the sleep need of sedentary young adults. Journal Of Sports Sciences, 31(4), 381-386. doi:10.1080/02640414.2012.733823


Copyright Susan Krauss Whitbourne, Ph.D. 2014


Photo credit: Erik Isakson / Getty Images