In exercise science literature a decreased capacity as well as a strongly reduced efficiency of the anaerobic metabolic pathway is awarded in children. The benefit and value of health of anaerobic training are questioned explicitly. Therefore the recommendations for endurance training with children in young age are usually focused on aerobic activities. In contradiction to this, an analysis of the self chosen leisure time movement patterns show that children prefer intermittent, explosive and intensive activities of very short duration. The aim of this study was to investigate how children and adults tolerate short intensive and intermittent anaerobic demands. 22 trained children (C) (13 girls: 10.6±1.4 yrs; 152±8 cm; 41.5±9.1 kg; muscle mass 22.1±4.4 kg; 9 boys: 9.7±1.1 yrs; 143±6 cm; 34.5±4.4 kg; muscle mass 18.8±2.3 kg) and 26 athletic trained adults (A) (12 women: 22.5±2.2 yrs, 169±4 cm, 58.0±4.1 kg, muscle mass 34.4±2.8 kg; 14 men: 23.0±2.4 yrs, 181±6 cm, 72.5±7.3 kg, muscle mass 45.6±4.2 kg) participated in the study. All athletes completed an identical intermittent sprint running protocol on an indoor track followed by an active (slow jogging) 30 min recovery. The protocol consisted of ten maximum 5 s sprints with a 40 s rest in between (2 min rest after 5 sprints). We recorded heart rate (HR), rate of perceived exertion (RPE) and 15m time (t 15) of each sprint as well as blood lactate concentration (LA) and blood pH (pH) pre-exercise, after 5 and 10 sprints (s 10) and during the post exercise recovery. The following results (mean ± standard deviation) were calculated using a multi factor ANOVA (main factors were age, sex and measurement time). Maximum LA and RPE were significantly lower (p<0.01) in children (LA 5.58±2.87 mmol/l, RPE 10.8±2.4) compared to adults (LA 10.02±3.07 mmol/l, RPE 16.7±1.8). Blood pH remained significantly higher (p<0.01) in children (pHs10 7.38±0.07) than in adults (pHs10 7.29±0.09). At similar sub maximum LA (6 mmol/l) pH remained higher in children. During recovery, the half time to reach a physiological LA was significantly shorter (p<0.01) in children (7.3±2.5 min) compared to adults (10.8±3.7 min). There was no significant difference in decrease of t 15 (t15 max - t15 min) between children and adults. A significant main effect of sex was only found for t 15m. We conclude that anaerobic intermittent exercises can be considered in athletic training with prepuberal children without any risk of a metabolic or psychological overload. The striking pH stability and the quicker recovery of the children point to an overall better regulated acid-base balance. Several recommendations in exercise science literature cannot be justified under consideration of our data.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Veröffentlicht von The Norwegian School of Sport Sciences. Alle Rechte vorbehalten.