By: Jason Lippman, MD
The motto of “exercise as medicine” has become a common phrase due to the progressing epidemics of diabetes, cardiovascular disease, and chronic pain that have ties to diet and body habitus. I prescribe it multiple times a day to my patients and I try to take a daily dose myself. But like all medications, it is important to remember what we are treating and to be wary of side effects. While we commonly measure exercise response in terms of “fitness,” fitness and health are not always the same thing. Fitness is just one component of overall health and it is very possible to be fit, but not healthy. 
Athletic fitness simply quantifies the body’s ability to move, perform, and compete. With consistent training, fitness can be achieved much quicker than health as a whole. As a result, the more immediate satisfaction of achieving fitness may easily lead to shortcuts that undermine a person’s overall health. There is a particular risk for top-level athletes as week-to-week performance potentially impacts income, which makes any long-term effects seem less pressing. One basic example can be seen in the high level of dental disease that has been reported in Olympic athletes – sometimes the basic things get sidelined due to focus on training.  However, it is definitely not just top competitors that have to be cautious to balance their exercise load.
I can speak from significant personal experience that it is exciting to test your body athletically and explore what you are capable of accomplishing. In fact, it can be so exciting that I routinely push through hard trail running workouts in spite of a lifestyle that includes limited time for sleep, an imperfect diet, and the desire for a beer at the end of the day. The result is that I have been able to make myself quite fit (at least for the moment); however, staying refreshed, replenished, and hydrated has become increasingly difficult. I have to continuously remind myself that by falling short of the overall healthy lifestyle to match the physical stresses to my body, I can expect it to catch up to me down the road. Overuse injuries are probably the most obvious risk – in fact, as I write this I am icing an aggravated foot. However, tunnel vision towards fitness affects our bodies in many ways across all of our different organ systems.
The most prominent examples of harm from overtraining are the Female Athlete Triad and Relative Energy Deficiency in Sport (RED-S). The Female Athlete Triad is a syndrome of metabolic and endocrine derangement experienced by female athletes that result from overtraining and nutritional deficiencies. Symptoms include a combination of progressive fatigue, menstrual irregularity, and low bone density that result in chronic exercise demands surpass restorative nutrition and rest. RED-S is the umbrella syndrome meant to describe the hormonal changes and low energy availability that result from overtraining in both female and male athletes. Sport medicine researchers have expanded RED-S impacts from the three cornerstones of the Female Athlete Triad – energy deficiency, menstrual function, and bone health – to also include impacts ranging from harm to cardiovascular health, immune system function, growth development, and psychological health in addition to several others. This article is not meant to become overly scientific, so suffice it to say that there are more and more data pointing to a crucial balance between exercise and recovery to ensure that good fitness translates into good overall health.
So, what do we do about it?
First, we take stock of our current habits and mentality with regards to exercise. Then, we look at the diet and recovery we are using to support our fitness and health goals. There are now apps like My Fitness Pal that work with fitness tracker devices to integrate our daily nutritional data with exercise data to help you review how well you are refueling. Some GPS watches and fitness apps like Strava even use heart rate data to estimate how well you have recovered between workouts so that you can step back and look for signs of overtraining. If you are a data junky – like some of us – this may be interesting and possibly useful information to have. There are still imperfections in the calculations and technology, but these devices can be a useful start, but don’t let them get in the way of any other signs your body is showing of wear and tear: i.e. recurrent aches and pains, fatigue, recurrent illnesses, etc.
Ultimately, you are in control of how you exercise and how often. You are also responsible for finding enough time for consistent meals and sleep to allow your body to recover and rebuild. Remember that managing nutrition and recovery can also be a team effort when needed. Just like having a coach or trainer to reach fitness goals, medical providers and nutritionist are great resources if you have concerns that your exercise regimen is being undermined by poor nutritional habits or low quality of sleep.
As in all respects, true health is a balance. Exercise is an amazing habit that improves mood, sleep, and health in addition to offering something for everyone. But, even the wonder drug of exercise needs to be tempered with rest and attention to recovery. Allow for easier recovery sessions on the days after hard workouts. Focus on keeping up with hydration and calories during the work day to net even on calories burned. Avoid exercise within the two hours prior to bed to allow your body to transition towards sleep. Brush AND floss your teeth.
And as always, see a medical provider if something seems to be going awry.
 Maffetone, PB and Larsen. PB. “Athletes: fit but unhealthy?” Sports Med Open. 2015;2:24. Epub 2016 May 26.
 Needleman, I et al. “ Oral health and elite sport performance.” Br J Sports Med 2015;49:3–6.
 Mountjoy M, et al. “The IOC consensus statement: beyond the Female Athlete Triad—Relative Energy Deficiency in Sport (RED-S)” Br J Sports Med 2014;48:491–497.
Jason Lippman, MD, is a third-year resident in the Division of Family Medicine at the University of Utah. His medical areas of interest include primary care, sports medicine, and population wellness.