Aspirin is an effective pretreatment for exercise in multiple sclerosis: A double-blind randomized controlled pilot trial.

Exercise benefits multiple sclerosis (MS) patients, but exercise-induced overheating is a deterrent for many. We conducted a double-blind crossover-design placebo-controlled pilot of aspirin to increase time-to-exhaustion (TTE) and reduce exercise-induced body temperature increase. A total of 12 patients participated. At enrollment, 8 of 12 reported heat sensitivity during exercise. After 650 mg of aspirin or placebo, participants performed lower body cycle ergometer exercise test. TTE increased after aspirin compared to placebo: t(11) = 2.405, p = 0.035 (Cohen's d = 1.45). Body temperature increase after exercise with acetylsalicylic acid (ASA) was reduced by 56% in heat-sensitive patients, although limited power precluded statistical significance. Aspirin may represent an effective pretreatment for exercise in MS.