SPECIAL COMMUNICATIONS: Letters to the Editor-in-Chief
Arlettaz et al. (2) have demonstrated that administration of therapeutic dosage of a glucocorticosteroid enhances endurance time at 70-75% of V˙O2max. It should be emphasized, however, that these results are probably only valid with low exercise intensity and do not hold for high-intensity exercise. With high-intensity exercise, other investigators failed to find a performance enhancement of corticosteroid administration (3-5). These results are in line with a recent, yet unpublished study in well-trained athletes who daily inhaled a glucocorticosteroid or placebo. So, the effect of corticosteroids on endurance performance is probably only true for relatively low-intensity exercise, and this also explains why Arlettaz et al. (1) in an earlier study failed to find an effect of glucocorticoid administration on endurance time. In their previous study, the exercise intensity was not 70-75% of V˙O2max, as used in the present study, but 80-85% of V˙O2max.
So, it appears not to be allowed to generalize the results of the latest study of Arlettaz et al. (2) to competitive sport where high-intensity exercise is required, because what counts for athletic performances is the highest possible intensity that results in the shortest time possible to cover a certain distance.
To the conclusion that this study is the first that showed an ergogenic effect of corticosteroid administration, one should add that this is only true for endurance time at an exercise intensity ≤ 75% of V˙O2max. With higher exercise intensities, no ergogenic effect of corticosteroids has been found so far (2-5).
Harm Kuipers, MD, PhD
Faculty of Health, Medicine and Life Sciences
Maastricht, The Netherlands
Babette Pluim, MD, PhD
KNLTB (Royal Dutch Lawn Tennis Federation)
Amersfoort, The Netherlands
1. Arlettaz A, Collomp K, Portier H, Lecoq AM, Pelle A, De Ceaurriz J. Effects of acute prednisolone intake during intense submaximal exercise. Int J Sports Med
2. Arlettaz A, Portier H, Lecoq AM, Rieth N, De Ceaurriz J, Collomp K. Effects of short term prednisolone intake during submaximal exercise. Med Sci Sports Exerc
3. Manohar M, Goetz TE, Hassan AS, Depuy T, Humphrey S. Anti-inflammatory agent, dexamethasone, does not affect exercise-induced arterial hypoxemia in thoroughbreds. J Appl Physiol
4. Marquet P, Lac G, Chassain AP, Habioux G, Galen FX. Dexamethasone in resting and exercising men. I. Effects on bioenergetics, minerals and related hormones. J Appl Physiol
5. Soetens E, DeMeirleir K, Hueting J. No influence of ACTH on maximal performance. Psychopharmacology