Free Radicals and Antioxidants


Oxygen is the fuel for long distance running. Oxygen enables the body to use glucose, which itself is produced from carbohydrates that we eat, for energy. This is why runners breathe so heavily when they exercise – the body is trying to intake as much oxygen as possible to drive the chemical reactions that produce energy for running. However, while oxygen is absolutely essential for running, it does have a serious negative – the production of free radicals.

Free radicals are a byproduct of the chemical reactions that allow for running. By definition, they are molecules that have unmatched electrons, and are produced by the increased presence of oxygen in the body. Upon losing an electron, a free radical will seek out and “steal” another molecule’s electron, thereby causing that molecule to be a free radical. This chain reaction can continue until cells of the body become damaged. This cell damage can lead to tissue damage and contribute to the formation of cancer in the body. Fortunately, there is a natural defense against free radicals that every runner should know about – antioxidants.


Antioxidants are the body’s best defense against free radicals because they are able to donate an electron to the free radical without becoming free radicals themselves. This stops the chain reaction and helps to prevent cell damage. While antioxidants are formed naturally in the body and increase in number as a runner trains harder, it is a good idea to supplement the natural antioxidants with proper nutrition. A runner can do a lot for his or her protection against free radicals by taking vitamin C and E supplements. Additionally, vegetables and fruits, including berries, especially blueberries, broccoli, garlic, and carrots all contain a number of antioxidants.

Understanding the importance of protecting the body from the damaging effects of free radicals is very important not only to running well, but also general well being of the body. By understanding how free radicals are produced by oxygen metabolism, and the necessary role of antioxidants in counteracting the harmful effects of free radicals, it becomes clear why eating plenty of fruits and vegetables is so very important to a runner’s health.

Image courtesy of Gordana Adamovic-Mladenovic


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