Journal Title (Medline/Pubmed accepted abbreviation): J. Strength Cond. Res.
Page numbers: 1126-1133
Summary of Background and Research Design
Background: Adolescents involved in intense training practices often consume inadequate amounts of vitamins, minerals, fluid, carbohydrates, and even energy. This can decrease their performance in sport and daily activities, and could potentially hinder growth and development.
Somatotype – an evaluation of body composition based on 3 classifications. Classifications include endomorphic (round, fat type), mesomorphic (muscular type), or ectomorphic (slim type). The variation in somatotypes decreases as the level of competition increases for many sports. The authors state that an individual’s somatotype will factor into an individual’s capacity of training for a particular sport.
Research goal: To assess the nutritional practices and the somatotypes of adolescent swimmers in order to provide individual advice to the athletes to improve their health and performance.
Subjects: Male (n=22) and female (n=14) swimmers, age about 14-16 yrs. old
Protocol:Anthropometrics (body measurements): height, weight, skinfold, body fat (calculated by the Faulkner equation and the Yuhasz method and measured by bioelectrical impedance). Measurements of the circumferences of the arms and legs were used to determine somatotype.
Nutrition: Intake of average macro- and micronutrients was gauged with a food frequency questionnaire. Nutritional status was evaluated by analyzing blood samples for glucose, cholesterol, triglycerides, iron, vitamin E, vitamin C, and carotenes (reports vitamin A).
Summary of research findings
- Males were statistically significantly taller and weighed more than females, but their BMIs were similar.
- Body fat percentage was highly variable for both boys (10.8% by Faulker method, 11.8% by Yuhasz method, and 17.4% by bioelectric impedance) and girls (12.8% by Faulker method, 15.6% by Yuhasz method, and 25.3% by bioelectric impedance), although girls, as expected, always had a higher percentage than boys, regardless of method.
- As expected, boys had a significantly higher caloric intake than girls (2845 ± 157 kcal/day for boys and 1789 ± 103 kcal for girls). This value seems particularly low for female athletes, and it is likely that at least 6 females underreported their intake.
- Energy intake was, on average, lower than the requirements for both sexes based on body size and physical activity level. More than 50% of both boys and girls displayed inadequate intakes of vitamins A, D, and E; carotenes; and folic acid. Most females showed inadequate intake of iron and calcium.With that said, all blood biomarkers were within a healthy range for these participants.
- Both males and females consumed an average of two-times the daily requirement for protein, but athletes require more protein than non-athletes.
- Males showed strong ectomorphic and endomorphic components, whereas females showed an even balance between ectomorphic, endomorphic, and mesomorphic characteristics. This is consistent with some previous literature, but also shows a higher endomorphic profile than a previous study with elite swimmers.
Interpretation of findings/Key practice applications
Adolescent athletes have greater energy and nutrient demands than non-athletes and must assure that they consume enough nutrient-rich foods. Although blood biomarkers were healthy among this population, intake for some key nutrients was inadequate including iron and calcium for girls and vitamins A and E for both genders. Analyzing the somatotype profile of young athletes may aid athletes and coaches to provide more individualized nutrition and training protocols to allow the athlete to capitalize on their string points while compensating for their weaker points.
As mentioned above, it appeared that there was underestimation of food intake in some of the subjects. This is a common problem in the assessment of dietary intake and it is possible that it may be exacerbated in athletes. In addition, it appears likely, based on the skinfold thickness values reported in Table 1, that bioelectric impedance may have overpredicted body fatness relative to the skinfold measurements.
It would have been interesting if the authors discussed the somatotype information further. For example, is it correlated with performance? Are there specific nutritional or physical protocols to follow to transform body type to include more or less of one of the components?