To analyze how physical fitness (PF) improves in elite junior tennis players related to age, maturity, and performance level.
Elite junior tennis players (n = 113 boys, n = 83 girls) divided by performance level were monitored longitudinally from U14 to U16. Maturity, upper and lower-body power, speed, and agility were measured during subsequent competitive seasons. Improvement was analyzed per sex using multilevel analysis.
PF components for boys and girls improved over age (U14-U16) (ES .53–.97). In boys, the more mature boys outscored the less mature boys in upper and lower-body power from U14-U16. In girls, high-ranked girls outscored lower-ranked girls on lower-body power, speed, and agility (U14-U16) (p < .05).
Boys and girls improved on all PF components during U14-U16. In boys, power was related to maturity. In girls, lower-body power, speed, and agility were related to tennis performance. This has important implications for talent development.
Kramer is with the HAN Sports and Exercise, HAN University of Applied Sciences, Netherlands and Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Netherlands. Huijgen, Elferink-Gemser, and Visscher are with the Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Netherlands.