Effects of endurance run on circulorespiratory system in young children

Twelve male young children of the experimental group, aged 5 and 6 years, who practiced a daily (except for Sundays) 915 m endurance run as the training program for 6 months, were tested before and after the training period with stepwise increased running velocities on the horizontal flat treadmill. Maximal running velocities, maximal heart rates, maximal oxygen uptakes in terms of body weight, and peak blood lactate concentrations obtained in maximal exertions of the last steps increased to significantly higher levels of the corresponding values than those observed before the start of training. But no significant improvements were found in the control group of 7 male young children who did not take part in the special program for fitness. On the other hand, no significant increases were observed in running velocities, heart rates, and oxygen uptakes equivalent to 4 and 3 mmol.l(-1)LA (4 and 3 mM LA) in both groups. A significant increase of the mean value of maximal oxygen uptake observed after the training period in the experimental group suggests the existence of circulorespiratory trainability also in young children. The most outstanding effect confirmed in the maximal running velocity for the experimental group was presumably mostly due to the increase of aerobic and anaerobic capacities.