(The information in this article was taken or adapted from the High Performance Coaching Program Study Guide.)
An important facet of physical development in the child and adolescent is the growth spurt. The changes in body size and rapid development that occur during this time period affect motor performance and training for tennis. For North American children, the growth spurt, which is characterized primarily by a peak change in stature or vertical velocity of growth, occurs around age 12 for females and age 14 for males. Note not only the two-year difference between males and females, but also the fact that females develop and mature sooner than males during this time period.
Another key area of physical growth and development is skeletal growth and development. The bones of the body grow from areas within the long bones called growth plates. These plates remain open during childhood and adolescence, and they close at different rates for males and females. In general, females’ growth plate closure is earlier than males’ (although adolescents do not reach complete skeletal maturity until ages 18 to 20). For example, the growth plates in the elbow area close at approximately ages 12 to 14 in girls, but not until ages 15 to 16 in boys. This area of bone maturation is particularly important in tennis players, as stresses imparted to the elbow area can lead to an irritation of the growth plate often referred to as “Little Leaguer’s Elbow” that can jeopardize performance. You need an understanding of the rate of bone growth and maturation in general in order to design training programs, including weight lifting and plyometrics, for your younger players.
Another difference between males and females during development is the presence of a significant developmental event. In females the initiation of menstruation (termed menarche) occurs typically one year after the peak velocity in vertical height, at approximately 13 years of age. No similar event takes place in males to signal rapid changes in development. Hormonal changes that occur during puberty in both males and females have significant effects on muscular development. Strength training for pre-pubescent individuals does not result in significant changes in strength or muscular hypertrophy, changes that can be seen with strength training in adolescents after puberty. While pre-pubescent athletes can use resistance exercise using body weight, bands or elastic resistance, and light weights with supervision, post-pubescent athletes will benefit to a greater extent from such training programs.