Exercised induced asthma in young male asthmatics with symptoms, and in remission.

A treadmill exercise test was carried out on 154 male subjects aged 15-25 years who gave a history of mild asthma in childhood, and on 31 similarly aged control subjects. The results were expressed as an exercise lability index, (ELI), based on measurement of FEV. The mean ELI of the control group was 7.6%, range 2.9-12.2% and a positive result in the asthma subjects was an ELI greater than 15%. Seventy five of the asthma subjects were found to have been asymptomatic for a year or more (group 1) and, in 15 of them (20%) the test was positive. The remaining 79 were currently symptomatic, or had been symptomatic within a year (group 2), and in 52 of these (66%), the test was positive. The difference between the two results was significant, p greater than or equal to 0.001. We believe this observation suggests that exercise induced asthma (EIA) cannot be demonstrated in the majority of asthmatics who are in remission.