Nineteen asthmatic boys (aged 13.4 years, 25-75 percentile: 11.5-15.1 years
) performed short bouts of maximal exercise (force-velocity test) to test t
heir anaerobic fitness and tolerance of maximal anaerobic exercise. Fourtee
n healthy boys (aged 13.9 years, 25-75 percentile: 11.6-15.7 years) matched
for anthropometric characteristics including lean body mass (LBM), puberta
l stage, and weekly physical activity formed a control group. The maximal a
naerobic power (W-ana) was measured during the force-velocity test. The max
imal oxygen uptake (V'(O2max)) was assessed during a standard graded exerci
se test. Pre- and post-exercise pulmonary function was measured by body ple
thysmography.
The asthmatic children exhibited lower W-ana than the control group (8.2 wa
tt kg(-1) LBM, 25-75 percentile: 7.55-10.6 vs. 11.3 watt.kg(-1) LBM, 25-75
percentile: 9.46-14.1; P=0.01). V'(O2max) was also diminished in the asthma
tic group (P=0.01). Multiple stepwise regression models revealed that Tanne
r's score (P < 0.001) and the diagnosis of asthma (P < 0.01) were the best
predictors of W-ana.
In conclusion, a diminished anaerobic fitness could contribute to the overa
ll exercise limitation in asthmatic children.