During and after exercise, reactive oxygen and nitrogen species are created. This causes oxidative stress that can impair exercise performance, contribute to muscle damage and interfere with recovery. Our bodies have strategies to counteract this oxidative stress. This includes an “endogenous antioxidant defence mechanism,” which means this defence mechanism is produced by our bodies. However, we also counteract this oxidative stress by consuming antioxidants through that food and beverages we consume. There are many types of dietary antioxidants. Some common ones include vitamin E, vitamin C, carotenoids, and flavonoids.  Our endogenous antioxidant defence mechanism and the dietary antioxidants that we consume work closely together to counteract this oxidative stress.

Because of the oxidative stress created by exercise and the impact that this can have on performance and recovery, antioxidant supplements are often recommended to athletes. However, while exercise increases our antioxidant requirements, exercise also increases the capacity of our endogenous antioxidant defence mechanism. This means our body can better handle the oxidative stress caused by exercise. Further, taking an antioxidant supplement may actually impair exercise performance. This is because these reactive oxygen and nitrogen species that antioxidants fight against may actually initiate the adaptive response to training. This means taking large doses of antioxidants may impair the exercise-induced training response by weakening this adaptive response. Essentially, taking an antioxidant supplement can prevent the full “gains” from grueling training sessions.

While taking an antioxidant supplement may impair performance, this doesn’t mean you shouldn’t consume a diet that is naturally rich in antioxidants. Antioxidants that are found naturally in food are not the same as antioxidants taken in a supplement form. Unlike supplements, alongside the antioxidants in foods are a range of other bioactive compounds that work with the antioxidants in a complementary manner. You don’t get these bonus compounds when you take an antioxidant supplement in isolation.

If you eat a well-balanced diet then it’s easy to get enough antioxidants through the foods you eat. Here are some examples of antioxidants and foods that they can be found in:

  • Vitamin C: bell peppers, citrus fruits, broccoli, strawberries
  • Vitamin E: almonds, sunflower seeds, avocado, peanut butter, vegetable oils
  • Flavonoids: berries, cherries, onions, cocoa, green tea, red grapes
  • Carotenoids: sweet potato, carrots, pumpkin, watermelon, grapefruit, cantaloupe

You’ll notice that this list includes a lot of fruits and vegetables. Your best bet is to eat a diet with a wide variety of bright coloured fruits and vegetables. This will help ensure that you’re consuming antioxidants as well as the various bioactive compounds that are also found in these foods.

What you eat or don’t eat will influence how you adapt to training. Aim to consume an antioxidant rich diet rather than taking an antioxidant supplement as this may actually impede training adaptations. Eating your antioxidants is also way more enjoyable than taking a supplement.

Categories: Megan Kuikman

Megan Kuikman

Hello! I’m Megan Kuikman. I’m a Registered Dietitian with specialized training in sports nutrition. My goal is to help athletes and active individuals achieve a healthy attitude towards health, training, and food. I empower athletes to fuel properly for training in order to restore their health and enhance performance. You can get in touch with me at: hello@megankuikmanRD.ca

1 Comment

Brad Beer · April 17, 2021 at 3:25 am

Great post Megan! Thank you

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