Purpose The main purpose of this study was to compare total run distances, which is an indicator of a player's aerobic capacity, in U16 and U17 junior categories in intermittent recovery Yo-Yo test. The secondary purpose was to find out physiological responses (maximum heart rate and maximum oxygen consumption value) in Yo- Yo intermittent recovery test (Yo-Yo IRT).
Material and method The monitored groups consisted of U16 category (n = 14, age = 15.5 +- 0.2 years, body height = 173.6 +- 7.8 cm, body weight = 64.5 +- 6.8 kg) and U17 category (n = 16, age = 16.4 +- 0.3 years, body height = 178.8 +- 6.4 cm, body weight = 70.6 +- 8.3 kg) players. To examine maximum aerobic capacity, Yo-Yo IRT was used.
This field test is focused on assessment of run distance, VO 2max and heart rate (HR). For statistical verification of research data, we used parametric t-test for independent samples, same variances, which were verified by Leven's test for equality of variances.
Probability of rejecting null hypothesis was set at the level of p<0.05. Results The average run distance in U16 players 1594.3 +- 287.1 m and U17 = 2002.5 m +- 331.9 m.
This difference was statistically significant t28 = -3.58; p<0.01 and equalled 20.4 %. The maximum value of heart rate (HRmax) in the younger players was HRmaxU16 = 198.9 +- 6.6 beat .min-1 and HRmaxU17 = 194.8 +- 6.8 heart rate.min-1.
The maximum oxygen consumption value (VO2max) was VO2maxU16 = 49.4 +- 2.7 ml.kg-1.min-1 and VO2maxU17 = 52.8 +- 3.2ml.kg-1.min-1 Conclusions These results are in accordance with theoretical knowledge which indicates that the players are able to achieve better performance in Yo-Yo IRT with increasing age or quality of competition.