Childhood growth and puberty play a crucial role in sports performance. Increases in testosterone, oestrogen, and androgenic steroids enhance muscle strength and size, improving performance and capability. However, challenges for young athletes arise from the wide variation in pubertal onset. A five-year window for the onset of puberty in boys and girls results in significant competitive challenges, particularly in contact sports, and may lead to attrition from sports. Peak bone mass and peak growth velocity are achieved during childhood, during which around 25% of total bone mass is developed, emphasising the need for adequate calcium and vitamin D intake. Participation in competitive sports during adolescence is associated with healthier body composition and higher bone density in adulthood. Before bone consolidation, long bones undergo rapid lengthening and are prone to fractures, while growth plates are weakest during rapid growth phases, making them susceptible to injury. While physical changes improve performance, there may be a temporary decline in balance and body control during adolescent growth. Rapid increases in height and weight affect the body’s center of gravity, impacting sports like figure skating and gymnastics.

Adipose tissue and energy homeostasis play key roles in pubertal onset and reproductive function. Changes in nutrition and energy availability to support athletic performance, where energy expenditure exceeds caloric intake, can dysregulate pubertal progression, particularly in females, due to functional hypothalamic hypogonadism. This can lead to delayed menarche, oligomenorrhea, amenorrhea, and negatively impact peak bone mass accrual. For adolescent females, menstrual cycle phases may impact sports performance. Finally, adolescence is a period of psychological maturation during which young people need support for their mental health to maintain their commitment to sporting activities.