Exercise-induced asthma and salt.

IF you suffer from exercise-induced asthma, a new study suggests that you might benefit from lower salt intake. Large studies of the incidence of exercise-induced asthma in the past have suggested a correlation with dietary salt intake--the higher the salt intake within a population, the higher the rate of asthma. This study examined the effects of restricted salt and elevated salt diets on pulmonary function and exercise in healthy controls and subjects who suffer exercise-induced asthma. Neither the low or high salt diets had any effect on the pulmonary function of healthy controls. But low salt intake improved post exercise lung function while high salt intake worsened lung function in those with exercise-induced asthma.

Exercise-induced asthma is a problem for nearly everyone who has asthma and it affects up to 40% of allergy sufferers, including 11% of Olympic athletes. Dietary salt is easy to manipulate and although reducing salt didn't eliminate exercise-induced asthma, it did significantly improve symptoms. If your workouts extend beyond an hour, don't restrict your salt intake too much-you do need sodium to maintain healthy fluid levels. In that case moderation, not abstinence, is key.

(Medicine and Science in Sports and Exercise, 2000, Vol. 32, No. 11, pp. 1815-1819)