Gymnastics

The number of young gymnastics competitors continues to increase, so it is especially important that growth, weight, bone health, eating behavior, and other developmentally important factors be carefully monitored. In gymnastics, small athletes have become the norm, and gymnasts themselves commonly view this small body image as ideal. Weight is a prevailing theme in gymnastics, regardless of the gymnastics discipline. Even in men's gymnastics, it is suggested that controlling energy intake to achieve lower weight is an appropriate and desired approach if a gymnast is to achieve success.³⁴ However, growth in children is expected, so there should be a concomitant expectation of increasing weight. Not recognizing this fact, many young gymnasts may try to achieve a low weight through unhealthy means. There is evidence that the delayed puberty and growth found in female gymnasts are most probably associated with an inadequate caloric intake.^35,36 Of course, inadequate caloric intake is associated with nutrient intake, and female gymnasts are at a particularly high risk of nonanemic iron deficiency, which could diminish health and performance.³⁷ Although it is true that lowering excess body fat will reduce body mass and, perhaps, lower the risk of traumatic injuries to joints, trying to achieve this through inappropriate means may also place the gymnast at risk.³⁸

Elite-level gymnastics has four separate disciplines, including men's artistic gymnastics, women's artistic gymnastics, women's rhythmic gymnastics, and women's rhythmic group gymnastics. Although the total time spent in gymnastics practice is high for elite gymnasts (up to 30 hours of practice each week), the actual time spent in conditioning and skills training is considerably less. Gymnasts begin practice with a series of stretches and then initiate a series of basic skills on the floor mat as part of the warm-up routine. After warm-up, each gymnast takes a turn practicing one of the events. The time performing a skill in practice never exceeds that of the competition maximum and is usually a small fraction of it. Because practice involves repeated bouts of highly intense, short-duration activities, gymnasts rest between each practice bout to regenerate strength (i.e., regenerate phosphocreatine). With the exception of the group competition in rhythmic gymnastics, none of the events within each of these disciplines lasts longer than 90 seconds. This maximal effort and short duration categorizes gymnastics as a high-intensity, anaerobic sport.

As anaerobes, gymnasts rely heavily on type IIb (pure fast twitch) and type IIa (intermediate fast twitch) muscle fibers.³⁹ These fibers, while capable of producing a great deal of power, are generally regarded as incapable of functioning at maximal intensity for longer than 90 seconds. Type II fibers have a low oxidative capacity, which limits fat usage as an energy substrate during gymnastics activity, and a poor capillary supply, which deprives these fibers of nutrient, oxygen, and carbon dioxide exchange during intensive work. Because of these factors, gymnastics activity is heavily dependent on creatine phosphate and carbohydrate (both glucose and glycogen) as fuels for activity.

A number of studies evaluating the nutrient intake of elite gymnasts have found inadequate intakes of energy, iron, and calcium.^40-42 Heavy gymnastics training and inadequate nutrient intake are implicated as causative factors in the primary amenorrhea experienced by many young gymnasts and may also contribute to the secondary amenorrhea experienced by older gymnasts.

Although inadequate calcium intake is associated with poor bone development and increased risk of stress fractures, inadequate iron intake is associated with anemia, a risk factor in the development of amenorrhea.⁴³

Keeping this in mind, gymnasts must consider the following nutritionally relevant factors for their sport.

Gymnasts are required to perform difficult tumbling and acrobatic skills that are easier for smaller people to do. Artistic gymnasts are commonly small (30th percentile for heightto-age ratio) but extremely muscular (90th percentile for arm muscle circumference).⁴⁰ This tendency for small stature may be due to a self-selection in the sport (i.e., only those who are naturally small remain in the sport competitively because they tend to be more successful) or because of an inadequate nutrient intake. Both of these factors are possible, either together or separately. Gymnasts and gymnastics coaches know that the top gymnasts tend to be small, so many try to achieve this small size by reducing food intake. There are numerous problems with this strategy, not the least of which is the possibility of delayed growth, with resultant poor skeletal development. In the relatively few cases where this occurs because of an overzealous coach or a gymnast who has made severe cuts in food intake, the outcome may be grim, leading to life-threatening eating disorders. Luckily, however, the vast majority of gymnasts do very well in this sport, have a high self-esteem as a result of participating in this sport, thrive as adults, and have healthy families.

Unhealthy athletes do not remain competitive, so it's in everyone's interest to eat enough to sustain health and growth. Toward that end, gymnasts should think more about optimizing body composition rather than achieving an arbitrarily low weight. A difficulty arising from low-calorie dieting is that weight goes down more from a loss of muscle than from a loss of fat. At some point the muscle loss will inhibit the capacity of gymnasts to perform the required skills, and the downward spiral in the muscle-to-fat ratio may cause gymnasts to further reduce food intake. The progressive reduction in food intake can eventually lead to an eating disorder, with all the dangerous implications that this involves.

Gymnasts are sensitive to the strength-to-weight ratio both from appearance and performance standpoints. It is impossible to avoid the reality that appearance is a factor in how highly a skill is scored. High strength enables gymnasts to more easily accomplish the required skill, and the appearance of effortlessness is a factor in the score (i.e., it enables an artistic gymnast to look more artistic). Gymnasts are constantly being reminded to smile while in competition, emphasizing that the performed skills are easily accomplished. The key is to be sufficiently conditioned and strong, factors requiring a stable muscle mass, so the skills can be completed with ease.

In a number of countries there is concern that gymnasts start learning skills too early, when they should be focusing on conditioning. A well-conditioned athlete can learn a skill more quickly and with a lower risk of injury. However, there are tremendous pressures on coaches to demonstrate that the gymnasts are making progress, and the best way to do that is to put them in junior competitions. A more balanced approach that focuses mainly on conditioning early in the gymnast's career while delaying the introduction of specific gymnastics skills may improve the skills acquisition learning curve later on.

To improve conditioning, gymnasts must consume sufficient energy and nutrients to meet the combined demands of growth, maintenance, and improvement in musculature. The focus of gymnastics training should be on getting strong, with a relatively low body fat percentage, rather than on staying (or getting) small, and this can only be accomplished through a training program that satisfies nutrition needs.

Gymnasts and many other female athletes have delayed menarche, which may play a role in bone health. Gymnasts failing to achieve menses by age 16 should see a doctor to determine the cause and, if needed, to seek a remedy. There are many possible causes for a delay or cessation of menses:

• Low body fat
• Poor iron status
• High physical stress
• High psychological stress
• High cortisol level (cortisol is a hormone produced by the body to counteract the soreness created from activity; it is commonly high in athletes and interferes with estrogen production)
• Low energy intake

It is conceivable that gymnasts may have all of these factors. Regardless of the cause(s), a delay in menstrual onset may negatively affect bone health and increase the later risk of early osteoporosis development. To reduce the risk of delayed menstrual onset, gymnasts should periodically assess both iron status and body composition to ensure a maintenance or enlargement of the muscle mass with age.

The competitive peak for female gymnasts is commonly reached at about age 16 to 18. With the exception of figure skating and diving, it is difficult to conceive of athletes who achieve this level of accomplishment at such a young age. For this to occur, a tremendous amount of time must be spent in conditioning and skills acquisition while the athlete is in the adolescent growth spurt. The combination of training and growth during these years places a tremendously high nutrition burden on the athlete that cannot be properly met without careful planning. However, with appropriate nutrition planning, it is possible to meet the combined needs of growth, physical activity, and tissue maintenance. Gymnasts who follow a sound nutrition program look better, perform better, enjoy the sport more, and stay in the sport longer.