Abstract
This study established the feasibility of an incremental maximum exercise protocol in asthmatic children. It investigated whether this protocol made it possible to satisfy the criteria for maximal exercise generally required in adults. Twenty-two asthmatic children (11 boys and 11 girls, mean age 6.86 years old) with clinically diagnosed mild to moderate asthma participated in this study. The incremental maximum exercise protocol was performed using a cycle ergometer with an electromagnetic braking (SportsArt C5150). Ventilation and gas exchanges were measured with a breath-by-breath automatic metabolic measurement system (COSMED K4 b2). The protocol was started at 40 watts for 2 minutes and stepwise increments of 8 watts every 2 minutes were applied. The pedaling frequency was set at 40 rpm. This protocol was found to be well tolerated by all asthmatic children. Most of the children reached the VO2 plateau (82%). A total of 77% of children satisfied the criteria for maximal respiratory exchange ratio (RERmax) of ≥1.0. Only 50% of children reached the predicted HRmax. It was concluded that this protocol was suitable for asthmatic children. Some of the criteria used for maximal exercise described in adults are rarely satisfying in children. Besides the clinical exhaustion, the best two criteria for assessing the maximality of the tests were the VO2 plateau and RERmax.