The Exercise Paradox

We have all heard it many times before –exercise is good for us. It can help us lose weight, strengthen our heart, lower blood pressure, help manage blood sugar and insulin levels, improve mental health, improve sleep and strengthen bones and muscles. But did you know that there is a potentially negative side to working out? Exercise also triggers oxidative stress. When we exercise, free radicals are generated as a natural byproduct of consuming oxygen to break down ATP (adenosine triphosphate) for energy.

While free radical production is part of the normal metabolic process, when an overload of free radicals accumulates, oxidative stress can ensue. Oxidative stress can damage DNA, accelerate aging, and lead to heart disease, diabetes, and cancer, among other chronic conditions.

Can Exercise Be Bad?

Exercise can be bad when you overdo it (you have heard the saying, too much of anything is not good!)  For example, high-intensity exercise for prolonged periods, exercising outside of your fitness level, and not letting your body rest and recover between workouts all have the potential to create more free radicals than antioxidants, which creates an imbalance and can overload your system and cause cellular damage.

Thankfully, our bodies have tools to protect us from free radicals. While exercise increases free radicals, it also increases the production of antioxidant enzymes. And research has shown that the short-term increase in oxidative stress disappears after a few days, as your body’s antioxidant reserve repairs the damage.


Fighting Free Radical Damage

To give yourself the best chance at fighting free radical damage, it is important to remember that in addition to our body’s own antioxidant system, the nutrients we consume are part of the body’s antioxidant defense system. Bolstering our intake of antioxidant-rich foods and nutrients will give you the best shot at protection against damaging free radicals and cellular damage.

A diet rich in Vitamin C, vitamin E, beta-carotene and other carotenoids, selenium, manganese, glutathione, coenzyme Q-10, alpha-lipoic acid, and other important antioxidants helps prevent oxidation and may boost your natural defense against free radical damage. That means you can enjoy all the benefits of exercise and worry less about any potential oxidative damage. That is a good thing for both your body and your health.



Kawamura, T., & Muraoka, I. (2018). Exercise-induced oxidative stress and the effects of antioxidant intake from a physiological viewpoint. Antioxidants, 7(9), 119.

Leaf Group. (n.d.). Oxidative stress and exercise: How it affects your health. LIVESTRONG.COM. Retrieved March 31, 2022, from

Powers, S. K., Deminice, R., Ozdemir, M., Yoshihara, T., Bomkamp, M. P., & Hyatt, H. (2020, May 4). Exercise-induced oxidative stress: Friend or foe? Journal of Sport and Health Science. Retrieved March 31, 2022, from,including%20blood%20and%20skeletal%20muscles.