The purpose of this study was to assess dietary intake and body composition of prepubescent girls competing in 3 aesthetic sports (artistic and rhythmic gymnastics and ballet). Because physiological demands of ballet training are similar to those in other aesthetic sports, ballet dancers were, for the purpose of this study, regarded as athletes. The sample consisted of 39 athletes (median age, 11 years, range 9–13) and 15 controls (median age, 11 years, range 10–12). Dietary intake was assessed using a quantitative food frequency questionnaire, and body composition, by means of anthropometry. There was no significant difference in total energy intake between groups, but there was a significant difference in energy substrate distribution. Artistic gymnasts reported significantly higher carbohydrate and lower fat contribution to total energy (57% ± 6% and 29% ± 5%, respectively) than rhythmic gymnasts (48% ± 6% and 36% ± 5%), ballet dancers (51% ± 4% and 34% ± 3%), or controls (51% ± 5% and 34% ± 4%). Relative to body weight, artistic gymnasts reported higher intake of carbohydrates (9.1 ± 4.2 g/kg) than rhythmic gymnasts (5.6 ± 3.1 g/kg), ballet dancers (6.6 ± 2.5 g/kg), or controls (5.4 ± 1.9 g/kg). Artistic gymnasts also had the lowest body-fat percentage among the groups. In all the groups mean reported daily intakes of most nutrients were higher than the current daily recommended intakes. The exceptions were dietary fiber and calcium. The proportion of athletes with an inadequate reported intake was highest for phosphorus (33%), followed by vitamin A and niacin (18%) and zinc (13%).
Maroje Soric, Marjeta Misigoj-Durakovic and Zeljko Pedisic
Marina Nikić, Željko Pedišić, Zvonimir Šatalić, Saša Jakovljević and Danielle Venus
The aim of this study was to assess the nutrient intakes of elite junior basketball players in comparison with nonathletes.
A previously designed food frequency questionnaire was undertaken by 57 male elite junior basketball players 15 to 16 years of age and 53 nonathlete peers.
Mean estimated energy intake was more than 700 kcal higher in basketball players than in the nonathletes (p = .002). In both groups estimated energy intake was ~14% from protein, 38% from fat, and ~48% from carbohydrates. For the basketball players, estimated protein intake was below 1.4 g/kg in 32% of the group and above 1.7 g/kg in 51%, while carbohydrate intake was below 6 g/kg in 56%. Percentages of participants who apparently failed to meet the estimated average requirement for micronutrients were higher in the nonathlete group. The nutrients most likely to fail to meet the recommendations for nutrient density were vitamin A (~70%), zinc (49% in basketball players and 30% in nonathletes), niacin and calcium (~30% for both micronutrients in both groups).
Within the limitations of the survey methodology, elite junior basketball players appear to consume higher absolute energy, macronutrient and micronutrient intakes than nonathletes, but the contribution of macronutrients to daily energy intake and the nutrient density of food choices was similar for both groups. Elite junior basketball players might benefit from nutrition education targeting carbohydrate and protein intake. Dietary modifications that increase intakes of vitamin A, zinc, calcium and niacin in the diets of both groups might also be of value.
Jozo Grgic, Filip Sabol, Sandro Venier, Ivan Mikulic, Nenad Bratkovic, Brad J. Schoenfeld, Craig Pickering, David J. Bishop, Zeljko Pedisic and Pavle Mikulic
Purpose: To explore the effects of 3 doses of caffeine on muscle strength and muscle endurance. Methods: Twenty-eight resistance-trained men completed the testing sessions under 5 conditions: no-placebo control, placebo control, and with caffeine doses of 2, 4, and 6 mg·kg−1. Muscle strength was assessed using the 1-repetition-maximum test; muscle endurance was assessed by having the participants perform a maximal number of repetitions with 60% 1-repetition maximum. Results: In comparison with both control conditions, only a caffeine dose of 2 mg·kg−1 enhanced lower-body strength (d = 0.13–0.15). In comparison with the no-placebo control condition, caffeine doses of 4 and 6 mg·kg−1 enhanced upper-body strength (d = 0.07–0.09) with a significant linear trend for the effectiveness of different doses of caffeine (P = .020). Compared with both control conditions, all 3 caffeine doses enhanced lower-body muscle endurance (d = 0.46–0.68). For upper-body muscle endurance, this study did not find significant effects of caffeine. Conclusions: This study revealed a linear trend between the dose of caffeine and its effects on upper-body strength. The study found no clear association between the dose of caffeine and the magnitude of its ergogenic effects on lower-body strength and muscle endurance. From a practical standpoint, the magnitude of caffeine’s effects on strength is of questionable relevance. A low dose of caffeine (2 mg·kg−1)—for an 80-kg individual, the dose of caffeine in 1–2 cups of coffee—may produce substantial improvements in lower-body muscle endurance with the magnitude of the effect being similar to that attained using higher doses of caffeine.