Anaerobic threshold alterations caused by interval training in 11-year-olds.

The purpose of this study was to examine the effects of the interval training on metabolic parameters at maximal work and at the anaerobic threshold in 11 year olds. The subjects were five healthy male children. They trained outdoor for 50 min a day, five times a week for six weeks, using interval work at 25 and 50% above their anaerobic threshold. Before and after training program, they performed a progressive exercise test on a cycle ergometer. During the last 15 sec of each power output measurements were made of oxygen uptake (VO2), carbon dioxide output (VCO2), heart rate (HR), ventilation (VE), ventilatory equivalent for oxygen (VEO2) and ventilatory equivalent for carbon dioxide VECO2). Following training, the group increased their anaerobic threshold (expressed as %VO2max) significantly (P less than 0.05) during the progressive exercise test, by 22%. Also at the anaerobic threshold level, increases were observed following training in CO2 output (VCO2-AT) and respiratory exchange ratio (R). Oxygen uptake (VO2, l.min-1) was increased by 19%, but the difference was not significant (P greater than 0.05). Maximal ventilatory equivalent for (VECO2max) decreased significantly (P less than 0.05). Maximal heart rate was reduced significantly (P less than 0.05). We conclude that training led to an increase of both anaerobic and aerobic metabolism, at any submaximal work above the anaerobic threshold, for this specific age group.