A study published in Allergy, Asthma & Clinical Immunology has found that Vitamin C reduced constriction of the airways (bronchoconstriction) resulting in coughing, wheezing and shortness of breath caused by exercise.

Physical activity increases oxidative stress when your body reacts with oxygen and as a consequence highly reactive molecules are produced known as free radicals.  Free radicals interact with other molecules within cells causing damage to proteins, membranes and genes.

Vitamin C

In several studies Vitamin C reduced oxidative stress which results from vigorous exercise. In a meta-analysis (a technique whereby the results of several studies are collated) it was found that Vitamin C halved the incidence of bronchconstriction post exercise and also in those participants who were undergoing heavy physical stress.

Harri Hemila of the University of Helsinki carried out a secondary analysis of a study of participants suffering asthma who experienced exercise-induced bronchoconstriction and concluded that Vitamin C may have substantial effects on the small airways.

Dr. Hemila concludes that “given the safety and low cost of vitamin C, and the consistency of positive findings in the nine randomized trials on vitamin C against exercise-induced bronchoconstriction and respiratory symptoms, it seems reasonable for physically active people to test whether vitamin C is beneficial on an individual basis, if they have documented exercise-induced bronchoconstriction or suffer from respiratory symptoms such as cough or sore throat after taking vigorous exercise.”

Vitamin C is widely available in supplement form but if you would prefer to get it through the diet the following foods are good sources: red and green peppers, kiwi fruit, oranges and grapefruit, strawberries, sprouts and broccoli.