The Effects of Biological Age on Speed-Explosive Properties in Young Tennis Players

Biological maturity can affect performance on motor tests, thus young players can have advantages or disadvantages during testing by being more or less mature than their peers of the same chronological age. The aim of this study was to investigate the effects of biological age on speed, agility, and explosive power in young tennis players. Fifty tennis players (age 12.3 ± 1.2 years, height 156.7 ± 12.8 cm, body mass 45.9 ± 8.9 kg) who were ranked up to 50th place in the ranking of the National Tennis Association, as well as up to 300th place on the international "Tennis Europe" ranking, participated in the study. They were divided into three groups according to their maturation status, that is, the peak height velocity (PHV) maturity offset: pre-PHV [<0] (n = 10); circa-PHV [0 to 1] (n = 10); and post-PHV [>1.5] (n = 25). They performed tests of speed (5, 10, and 20 m sprints), agility (20 yards, 4 × 10 yards, T-test, TENCODS, and TENRAG), and explosive power (countermovement jump, one-leg countermovement jump, squat jump, long jump, and one-leg triple jump). Results showed significantly higher height of the vertical jump in the post-PHV group compared to the pre-PHV group, in the range of ~16% to ~27%. Moreover, linear and change of direction speed was significantly faster in the post-PHV group compared to the pre-PHV group, in the range of ~5% to ~8%. Height of the squat jump and speed in the T-test were significantly better in the post-PHV group compared to the circa-PHV group, in the range of ~7% to ~15%, while height of the single-leg triple jump was significantly higher in the circa-PHV group compared to the pre-PHV group by ~7%. This study showed that tennis players of older biological age achieve better results in almost all variables of speed, agility, and explosive power compared to players of younger biological age. Coaches should be aware of the differences found in physical performance and consider the practical implications that maturation can have in the long-term development of young tennis players.