When you exercise, your active muscles and organs produce molecules – one group of these are free radicals and reactive oxygen species. They have the potential to damage your cells, and they’re called pro-oxidants, or oxidants for short. In a healthy person, the body has its own supply of antioxidants that it uses to disarm these oxidants and protect its cells from damage. When there’s too many oxidants for the body to handle, it’s called oxidative stress. Chronic oxidative stress leads to inflammation and is implicated in a wide range of health conditions such as cancer, diabetes, cardiovascular and neurodegenerative diseases.
It’s important to know that oxidative stress is a normal by-product of exercise. The production of these oxidants through exercise increases key antioxidant enzymes in your muscles which assist with muscle regeneration. This is one of the ways your body positively adapts to increased training loads – both intensity and duration. Also, certain oxidants (like nitric oxide) are important signallers that help your body to maintain optimal functioning while working hard under exercise-induced stress via other processes like good blood flow and insulin sensitivity.
So, while uncontrolled oxidative stress is unhealthy, it appears that controlled oxidative stress such as that produced by regular aerobic exercise has an important role in sport performance and overall health status. Trained athletes tend to have higher levels of adaptation and fewer overall health risks than ‘weekend warriors’. This is good news for endurance athletes. Interestingly, a long-term history of endurance activity may also reduce age related oxidative stress in masters’ athletes. By comparison, sports which involve frequent bouts of high intensity (anaerobic activity) like football, rugby and soccer can overwhelm the body’s antioxidant defence system and result in fatigue and injuries.
Should you take antioxidant supplements?
It isn’t generally recommended to take antioxidant supplements as they can suppress your body’s natural response to physical activity. Studies using supplementation with common antioxidants such as vitamin C and E and green tea extract haven’t found improvements in athletic performance or post-activity muscle damage; and some studies have even shown that supplemental antioxidants reduce the normal training adaptations in muscles, which has a detrimental effect on performance.
There are a few types of athletes who may benefit from antioxidant supplementation: elite athletes who do a lot of high intensity activity and those in contact sports who may be at risk of neurodegenerative disorders caused by head trauma injuries; also athletes with upper respiratory conditions like asthma and allergies. These people are more at risk of an oxidative stress overload, and for them some antioxidants such as omega-3 and N-acetylcysteine appear to be helpful in reducing inflammation and muscle damage.
Fill your plate with natural antioxidants
Studies on the health effects of antioxidant supplements for preventative medicine and general wellness are conflicted. You may not need any additional antioxidants and taking more than you need isn’t always a good thing for your health. However, exercise is only one of many factors that causes oxidative stress in our modern lifestyle, so it’s wise to give your antioxidant system some help.
Plant-based eating is an excellent way to give your body a natural dose of vitamins, minerals, antioxidants and anti-inflammatory compounds every day. Eating a variety of fruits, vegetables, nuts, seeds, legumes and grains every day will top up your reserves of essential nutrients but won’t negate the positive training adaptations you need to achieve performance improvements.
After exhaustive endurance training or racing, a high antioxidant food or supplement powder may assist in reducing inflammation and speeding up your recovery, so that you can return to training or competition quicker. This is a good time for a smoothie full of dark leafy greens and blueberries – or a juice such as blackcurrant or tart cherry.
If you want to know more about the benefits of plant-based eating for your sports performance, check out my post Power Your Performance with Plants. You can also read all about the benefits of NZ blackcurrants here.