Marathon Training 101: Best Foods for Immunity

Marathon Training 101: Best Foods for Immunity

The harder you push yourself during physical activity, the harder your immune system has to work. Initially, there's a positive correlation between exercise and immune response. However, if an athlete over-trains or pushes too hard, immune system function can decline, leaving an athlete more susceptible to infections and illness. This is where nutrition comes into play!

Here are some great foods you can include in your training to keep your immune system in top shape!

Nutritional Yeast

A recent study showed that by including a special fiber found in Brewer’s yeast and nutritional yeast, marathon runners were able to decrease their chance of developing a respiratory infection weeks after a marathon. Not only did their illness rates decline, but they also reported feeling better physically and emotionally versus those who were taking a placebo.

So what is nutritional yeast? Nutritional yeast is a deactivated yeast, often a strain of Saccharomyces cerevisia, that is sold as a food. You can find it at most health food stores as a yellow, flakey powder. It is widely used in vegan and vegetarian cooking as a cheese substitute and has a creamy, cheese-like flavor. You can even sprinkle it over some popcorn instead of butter, incorporate it into salad dressings or throw a spoonful into a Blast. It is a good source of B12, a variety of other B vitamins, fiber and trace minerals.

Including nutritional yeast into your daily diet can help enhance immune function, decrease saturated fat intake by swapping out cheese and butter and it's a good source of B-12, which can keep energy levels high.


A powerful flavonol, quercetin is an important component of a healthy athletic diet. Due to its cardioprotective, antioxidant and anti-pathogenic properties, higher levels in the blood have been associated with a decreased risk for respiratory infections in athletes.

Incorporating foods like onions, apples, blueberries, curly kale, hot peppers, tea and broccoli into Blasts and daily eating plans can help boost immunity.

An even greater effect was found when quercetin-rich foods were combined with EGCG found in teas, n-3-polyunsaturated fatty acids found in salmon, hemp seeds, sardines, walnuts and flax seeds.


Your immune system starts with a healthy gut! A healthy gut is defined by healthy bacteria, also known as probiotics. A balanced gut, with adequate amounts of friendly bacteria will help keep disease-causing bacteria at bay. Recent research has shown a positive correlation between probiotics and a decreased rate of respiratory illness among athletes. In order to increase probiotics in your diet, you can take a supplement or include foods like kefir, sauerkraut, pickles, yogurt with live active cultures, miso soup and kombucha.

If you're considering using a probiotic supplement, look for a well-known and trusted brand with 15 billion live cultures per serving and several different strains - your best options are bifidus and l-acidophilus.


Broccoli contains a compound called indole-3-carbinol that has been shown to turn on immune function. Having an active immune system can ensure foreign bacteria will be cleared from the body before they can do any damage. Staying healthy over the next four months is crucial to having a positive experience come race day!

Vitamin C

There has been a lot of debate in the past over the effects of Vitamin C in preventing colds and shortening their length. Research has shown that adequate amounts of Vitamin C may not prevent a cold, but may decrease the duration of a cold. However, more positive research has been shown with marathon runners. The research has found that runners who had higher levels of vitamin C in their diets decreased their chance of getting a cold by 50 percent. Great sources include kiwi, oranges, papaya, green peppers, raw cabbage, cantaloupe and green leafy vegetables.

Try this Immunity Boost Blast for a stronger immune system!

Registered Dietitian, Certified Specialist in Sports Dietetics

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