Asthma and exercise : climatic effects upon exersice-induced bronchoconstriction and exercise capacity in asthmatic subjects

Abstract

The present thesis consists of five studies with the main objective to investigate the effect of different climatic conditions upon exercise capacity and exercise-induced bronchoconstriction (EIB) in subjects with diagnosed EIB (reduction in forced expiratory volume in 1 second (FEV1) ≥ 10% from before to after exercise). In order to assess exercise capacity measured by peak oxygen uptake (V& O2 peak) and peak minute ventilation (V& E peak), two different exercise protocols were evaluated. The usefulness to diagnose EIB in medium altitude by a competitive cross-country skiing field test was compared to assessment of methacholine induced bronchial hyperresponsiveness (BHR) in elite cross-country skiers.

Paper I: Stensrud T. and Carlsen K-H. Can one single test protocol for provoking exercise-induced bronchoconstriction also be used for assessing aerobic capacity? Clin Respir Jour 2008. In press.

Paper II: Berntsen S., Stensrud T., Ingjer F., Vilberg A., Carlsen K-H. Asthma in medium altitude - exercise-induced bronchoconstriction in hypobaric environment in subjects with asthma. Allergy 2005 Oct; 60(10):1308-11.

Paper III: Stensrud T., Berntsen S., Carlsen K-H. Humidity influences exercise capacity in subjects with exercise-induced bronchoconstriction (EIB). Respir Med 2006 Sep; 100(9):1633-41.

Paper IV: Stensrud T., Berntsen S., Carlsen K-H. Exercise capacity and exerciseinduced bronchoconstriction in a cold environment. Respir Med 2007 Jul; 101(7):1529-36.

Paper V: Stensrud T., Mykland K.V., Gabrielsen K. and Carlsen K-H. Bronchial hyperresponsiveness in skiers: field test versus methacholine provocation? Medicine and Science in Sports and Exercise Med Sci Sports Exerc 2007 Oct; 39(10):1681-6.