Benefits and problems of a physical training programme for asthmatic patients.
The clinical and physiological effects of a medically supervised, indoor physical training programme were investigated in 36 asthmatic subjects aged 16-40 years. After clinical evaluation, lung function assessment, and progressive incremental exercise testing subjects were randomly allocated to control and training groups. The measurements were repeated after a six week run in period and after a further three months in which those in the training group underwent an indoor training programme. The measurements made at three months were compared with those at the end of the run in period. There was no significant change in anthropometric characteristics, blood lipid profiles, or the provocative concentration of histamine causing a 20% fall in FEV1 (histamine PC20) in the group who underwent training. After training there were significant increases in mean maximal oxygen uptake (ml kg-1 min-1) from 23 (5) to 28 (6), oxygen pulse (ml/beat) from 8.8 (2.3) to 10.8 (2.4), and anaerobic threshold (1/min) from 1.11 (0.27) to 1.38 (0.33). These changes were significantly greater in the group undergoing training than in the control group. There was also a significant fall in breathlessness scores (Borg ratings), blood lactate, carbon dioxide output, and minute ventilation during submaximal exercise in the training group, with no change in the control group. The subject's motivation, the initial level of fitness, and the symptom score at the time of training were the most important factors influencing improvements in cardiorespiratory fitness. Thus submaximal physical exercise of controlled intensity, sustained for three months, produced significant improvements in fitness and cardiorespiratory performance that should be advantageous to the exercising asthmatic patient. The availability of medical supervision throughout the exercise programme appears to have contributed to the successful outcome.