Effects of swimming training on aerobic capacity and exercise induced bronchoconstriction in children with bronchial asthma

Background-A study was undertaken to determine whether swimming training im proved aerobic capacity, exercise induced bronchoconstriction (EIB), and br onchial responsiveness to inhaled histamine in children with asthma. Methods-Eight children with mild or moderate asthma participated in swimmin g training every day for six weeks. The intensity of training was individua lly determined and set at 125% of the child's lactate threshold (LT), measu red using a swimming ergometer. Another group of eight asthmatic children s erved as control subjects. Aerobic capacity and the degree of EIB were asse ssed by both cycle ergometer and swimming ergometer before and after swimmi ng training. Results-The mean (SD) aerobic capacity at LT increased by 0.26 (0.11) kp af ter training when assessed with the swimming ergometer and by 10.6 (4.5) W when assessed with the cycle ergometer, and these changes were significantl y different from the control group. The mean (SD) maximum % fall, in forced expiratory volume in one second (FEV,) to an exercise challenge (cycle erg ometer) set at 175% of LT decreased from 38.7 (15.4)% before training to 17 .9 (17.6)% after training, but with no significant difference from the cont rol group. There was, however, no difference in histamine responsiveness wh en compared before and after the training period. Conclusion-A six week swimming training programme has a beneficial effect o n aerobic capacity but not on histamine responsiveness in children with ast hma.