Moderate physical activity among children is beneficial for growth. In fact, exercise in childhood is critical for maximizing bone growth and preventing osteoporosis in later years. However, when exercise levels increase to vigorous and extreme levels for prolonged periods of time, negative growth effects may occur. Children who engage in sports with an emphasis on caloric restriction and high energy expenditure are at the greatest risk for retarded growth. According a study published in the "Annals of the New York Academy of Sciences", inadequate nutrition during the prepubescent stage will delay puberty and stunt growth.
Children participating in advanced to elite levels of gymnastics experience a particular pattern of skeletal maturation and growth. Artistic gymnasts, both male and female, experience a reduction of growth potential, but this is particularly pronounced in males. Among rhythmic gymnasts, a female’s genetic predisposition for growth is not reduced, but significantly delayed. In both artistic and rhythmic gymnasts, the prepubescent phase is prolonged and puberty shifts to a later age. This delay or lack of growth may result from continuous impact to joints and bones. A 2010 study published in “Annals of the New York Academy of Science” reports that the stunted growth is because of reduced caloric intake coupled with high energy expenditure, which physiologically alters glands and hormones in the body.
Wrestlers often engage in unhealthy weight-loss practices to qualify for less-competitive and lower weight class. Some wrestlers may start in the sport as young as 8 years of age. Depending on the intensity of dieting and exercise, their growth may be slowed or stunted as a result. On average, wrestlers competing in high school tournaments are shorter than their counterparts. During the wrestling season, significant reductions in fat mass, body weight and body fat have been observed in wrestlers, according to a study published in “International Journal of Sports Medicine.”
Long-distance running requires prolonged stamina at a level of high intensity. For runners to carry their bodies with ease, low body weight is emphasized. As a result, runners consume fewer calories in relation to energy expended and fat burned. Female long-distance runners often experience amenorrhea, the absence of a menstrual cycle. According to a study published in “Calcified Tissue International,” female long-distance runners with amenorrhea possessed decreased bone mass density in their skeletal frames. While height among long-distance runners appears average, skeletal bone structure can be weakened or compromised by the demands of the sport, as noted by a 2007 study published in the "International Journal of Sports Medicine."
Advanced ballet dancers may train for five hours or longer per day, while restricting their caloric consumption. Ballets dancers are shorter in stature during their prepubescent years than their non-ballet counterparts. Ballerinas and long-distance runners are the only athletes found to possess low body mass in relation to their height, according to a 2002 study published in the “British Journal of Sports Medicine.” Because of extreme caloric restriction and high energy expenditure, ballet dancers experience a delayed growth phase and postponed menstruation. Ballerinas follow a similar growth pattern to rhythmic gymnasts, whose genetic predisposition for growth is not compromised, only delayed. After puberty, ballet dancers usually reach full genetic potential for height. However, bone density and mass may continue to be compromised as a result of restrictive diets.