The effect of prolonged submaximal warm-up exercise on exercise-induced asthma

Area of Science:

• Exercise Physiology
• Pulmonary Medicine
• Sports Medicine

Background:

• Exercise-induced asthma (EIA) is a common condition affecting athletes.
• Standard exercise protocols can trigger significant bronchoconstriction in individuals with EIA.
• The potential for a warm-up period to mitigate EIA symptoms requires further investigation.

Purpose of the Study:

• To investigate the effect of a prolonged warm-up exercise on exercise-induced asthma (EIA).
• To determine if a warm-up can induce refractoriness to EIA without causing significant bronchoconstriction.

Main Methods:

• Seven asthmatic subjects with known EIA underwent two randomized exercise protocols on separate days.
• Protocol A: Standard 6-min run (S1A), followed 45 min later by an identical run (S2A).
• Protocol B: 30-min lower-intensity run (W1B), followed 21 min later by a standard 6-min run (S2B).

Main Results:

• The second exercise test in Protocol A (S2A) showed reduced EIA compared to the initial test (S1A), indicating refractoriness.
• Protocol B's warm-up (W1B) resulted in significantly less EIA than S1A.
• The subsequent standard run in Protocol B (S2B) also demonstrated significant refractoriness to bronchoconstriction, comparable to S2A.

Conclusions:

• A prolonged warm-up period of exercise can induce refractoriness to exercise-induced asthma (EIA).
• This warm-up effect can occur without inducing marked bronchoconstriction in individuals with EIA.
• Warm-up protocols may serve as a strategy to manage EIA during physical activity.