Training Intensity and Age

Young athletes nowadays can safely train and develop skill levels unmatched by their predecessors but the intensity of the training must be closely monitored. During this phase of development intensive training programs can expose young athletes to health risks not seen in adults. The health risks are related to an increased risk of injury to the growth centres of the immature skeleton, as well as the effects on overall growth, maturation, and psychological well-being.

The young athlete's skeletal uniqueness of growth cartilage is the essence of their physical vulnerability to injuries as compared to adults. The presence of areas of bone cartilage maturation and the relative weakness of these areas compared with ligaments and tendons are significant factors in injuries in young athletes. The development of bone and soft tissues at varying rates provides additional risk to the pre-adolescent who, during periods of rapid growth ('spurts') loses flexibility.

Growth cartilage is present at three main important sites: at the growth plate itself (physis); at the joint surface in the form of articular cartilage; and at the site of major muscle-tendon insertion (apophyses). An injury at the growth plate can occur from direct trauma or repetitive forces which can cause irregularity, widening, or premature closure of the growth plate (physis) leading to permanent growth disturbance. An injury to the articular cartilage increases the risk of premature osteoarthritis over the ages of forty or fifty and can cause osteochondritis dissecans which are lesions on the joint surfaces that usually occur in a person's twenties. The apophyseal areas (i.e. attachment of knee cap tendon) are vulnerable to repetitive traction forces and are often implicated in preadolescent overuse injury. The apophyseal areas are very susceptible to traction type overuse injuries with rapid growth and loss of flexibility (see diagram). These overuse injuries can be treated with early intervention and modification of activities to prevent long-term complications in growing athletes. The majority of overuse injuries can also be prevented with appropriate training programs where coaches, parents and medical personnel acknowledge the particular susceptibility of young athletes and provide education, guidance and monitoring of physical maturation and early intervention, as well as treatment of injuries.

Although the typical age of puberty and growth spurts in girls is age 11-14 and 12-15 in boys, young athletes in some sports, such as figure skating, tend to be delayed in this phase for up to two years compared to the normal population. It has been shown that as the duration of intense training increases there is also an increase in the delay of physical development, growth and sexual maturation. Lateness in maturation has also been associated with nutritional deficits and lower fat mass. Delay in the first menstruation cycle for females or interruption of their normal menstruation (primary and secondary amenorrhea) secondary to over training is associated with a reduction in trabecula bone density thus increasing the risk of stress fractures in the short term and predisposing them to osteoporosis in the long term.

Young high performance athletes should be encouraged to train and compete in an environment that promotes normal physical development and not one which suppresses growth and delays sexual maturity. In figure skating, for example, age categories for competition should reflect the medical concerns regarding the rapid developmental stage in adolescents.

Dr. Jane Moran is a physician practicing in Victoria. She is a specialist in emergency medicine and has been the chair of the International Skating Union's Medical Committee for the past several years.

Copyright held by SportMedBC. For information contact