Reconditioning in asthma and sporting activities: principles of tailored physiological training

Even asthmatics free from airway obstruction complain of exercise discomfor t, early hyperventilation with muscle fatigue and reduced tolerance for pro longed performance. As hyperventilation is considered a potent stimulus to exercise-induced asthma, sporting activities are often restricted for these patients, leading to inactivity and muscular deconditioning. The downward spiral that leads from respiratory disease to deconditioning can be interru pted by rehabilitation, which afterward allows most athletic activities. We use a tailored bilevel endurance training programme (TBEP), the intensity of which is based on a pretraining maximal test evaluation. During TBEP the patient exercises 30 minutes 3 days a week for 6 weeks (18 sessions) on an ergocycle. Each session alternates a base phase of 4 minutes at the ventil atory anaerobic threshold intensity, and a peak phase of 1 minute at the ma ximum tolerated intensity. Following the 'overload principle', base and pea k phase intensifies are raised in increments of 10% as soon as the training effect induces a target heart rate decrease of 10 beats/min. The beneficia l changes that result from a 6-week TBEP consist of: reduced breathlessness and a + 20% increase in the maximal test values, intensity and oxygen upta ke. At a given submaximal level of work, ventilation and heart rate values show a 30% decrease. Maintaining fitness is obtained if a 30-minute session is performed once or twice a week at the B/P intensities reached during th e 18th session; if these intensities are then increased following the overl oad principle substantial physiological improvements are continually obtain ed. (C) 2001 Editions scientifiques et medicales Elsevier SAS.