Outpatient exercise training in children with cystic fibrosis: Physiological effects, perceived competence, and acceptability

Exercise training is currently advocated as part of the treatment of patien ts with cystic fibrosis (CF). However, data are few that document physiolog ic benefits or changes in patients' perceptions of long-term training progr ams in children with CF. The aim of this study was to investigate the effec ts and acceptability of a home cycling program in children with CF. Fourtee n patients (9 boys, 5 girls) with CF, mean (SD) age 14.1 (2.0) years, with mild to moderate impairment of lung function (forced expiratory volume in 1 s, mean (SD) 58.3 (16.3)% of predicted) were studied for 1 year. The first half of the study year was used to obtain baseline values at 0 and 6 month s. During the second half of the year, a cycle program was carried out 5 ti mes a week, for 20 min each day at a level of work that resulted in a heart rate of 140-160 beats/min. Once a week the cycle program was supervised by a physiotherapist. Measurements were repeated at 12 months. Effects of the exercise program were measured in terms of lung function, nutritional stat us, growth, muscle strength, exercise performance, perceived competence, an d attitude towards the training program. Differences between the changes du ring the 6-month training period as compared to the g-month control period were analyzed by multivariate statistics and nonparametric tests. Statistically significant differences (P < 0.05) between the two periods we re found with respect to muscle strength of knee extensors and ankle dorsif lexors, and with respect to maximal oxygen consumption per kg body weight a s well as per kg fat free mass. All changes were positive. No adverse effec ts were found. Perceived competence showed significant positive changes in feelings about physical appearance, general self-worth, and Total Perceived Competence Score. Scores concerning perceived acceptability of the program were significantly lower at the end of the training period; however, patie nts reported that they did want to continue with other sorts of training. We conclude that an exercise training program in the home can produce benef icial effects on oxygen consumption, muscle force, and perceived competence in children with CF. However, acceptability of the program was low, sugges ting that long-term adherence would be poor, and hence, other sorts of trai ning need to be identified. (C) 1999 Wiley-Liss, Inc.