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Dietary energy density (kcal/g) is defined as available dietary energy per unit weight or volume of food. The consumption of energy-dense foods has been associated with increased obesity risk and with excessive weight gain. The objectives of this study were to compare how dietary energy density, calculated using three different methods relates to food choices and nutrient composition of the diets of elite figure skaters. Participants were 159 elite figure skaters attending training camps. Mean age was 18.4 y for boys (n = 79) and 15.9 y for girls (n = 80). Heights and weights were measured to calculate body-mass indices (BMI). Dietary intakes were based on 3-d food records analyzed using the Nutritionist IV program. Mean energy intakes were 2326 kcal/d for boys and 1545 kcal/d for girls. Dietary energy density, based on foods and caloric beverages only, was 1.0 kcal/g. Dietary ED was positively associated with percent energy from fat and negatively with percent energy from sugar. The main sources of dietary energy in this group were baked goods, cereals, regular soda, low-fat milk, fruit juices, bagels and pizza. Percent energy from fast foods was associated with higher dietary energy density, whereas percent energy from dairy products, soft drinks, vegetables, and fruit was associated with lower dietary energy density. These results are consistent with past observations; higher energy density diets were higher in fat. In contrast, there was a negative relationship between sugar content and energy density of the diet.

Our aim in this study was to determine the body fat percentage of teenagers in Diyarbakir, a city in southeast Turkey. The study included 1118 children between the ages of 10 to 15. Basic anthropometric measurements including body-mass index (BMI) and skinfold thickness were taken. The skinfold thickness were measured with a Lange skinfold caliper. Fat mass percentage (FM %) was predicted by using skinfold thickness equations. Differences between boys and girls across age groups for weight, height, and BMI were found to be statistically significant (P < 0.0001). With respect to skinfold thickness in the 10-y-old group, the thickness at triceps and subscapular sites in girls was higher than those of boys. In the 12-y-old group, the thickness was found to be higher in girls than boys at the triceps, biceps, and subscapular sites. We found that an increase in skinfold thickness in the 13, 14, and 15-y-old groups was significantly higher among girls than boys and tended to increase with age. However, such a tendency was not shown in boys. This tendency was found only at the triceps site in 10, 12, and 13-y-old boys. In addition, the skinfold thickness at the biceps site was found to be greater in the 14-y-old boys. The body fat mass percent in girls, especially those older than age 13, was also increased.

The determination of blood glucose response to various carbohydrate foods may help athletes in their choice of preexercise feedings. This case study documented the postprandial glycemic responses of three male endurance athletes at rest after ingestion of 50-gram portions of three carbohydrate foods: graham crackers, orange juice, and oatmeal. Plasma glucose response differed in each subject for each test food. Two of the three subjects exhibited similar glycemic responses, but not to the same test food. Future studies will clarify the relationship between carbohydrate ingestion and postprandial glucose response.

This study examined whether ribose supplementation before and during intense anaerobic exercise impacts anaerobic capacity and metabolic markers. Twelve moderately trained male cyclists (22.3 ± 2.2 y; 181 ± 6 cm, 74.8 ± 9 kg) participated in the study. Subjects were familiarized and fasted for 8 h after standardizing nutritional intake. In a double blind and crossover manner subjects ingested either a 150 mL placebo or ribose (3 g ribose + 150 μg folate). Subjects rested for 25 min and completed 5 × 30 s anaerobic capacity tests with 3 min passive rest. Six capillary blood samples were taken prior to and after sprints for adenine nucleotide breakdown determination. The experiment was repeated 1 wk later with alternative drink. Data were analyzed by repeated measures ANOVA. No significant interactions were observed for any performance or blood variables. D-ribose supplementation has no impact on anaerobic exercise capacity and metabolic markers after high-intensity cycling exercise.

The effect of fungal carbohydrases (Carbogen™ [C]) consumed with a meal replacement bar (MBR) on glucose metabolism and exercise performance was determined in 5 male competitive cyclists. After a 12-hour fast, subjects performed two 60-min cycling bouts at 80% V̇O_2max followed by a time-to-exhaustion (TE) ride at 100% V̇O_2max. One hour prior to each cycling bout, subjects ingested a MRB + 160-mg C or 160-mg CaCO3 placebo (PL) in a double-blind, counterbalanced fashion. Blood was drawn for determination of glucose, insulin, and lactate at: fasting, 1 hour post-feeding, minutes 30 and 60 of exercise, and after TE. Two-way ANOVA revealed a significant (p < .05) treatment and time effect for glucose, with C being higher than PL. Interaction effects were ob-· served for insulin and lactate. An increase in TE (min) at 100% V̇O_2max was observed in the C versus PL trial (6.3 ± 3.4 vs. 4.4 ± 2.9, p < .001). A MRB+C may benefit cyclists due to increased BG and improved exercise performance.

The purpose of this study was to determine the effect of a high vs. a low preexercise carbohydrate (CHO) diet on performance during multiple sets of resistance exercise. Eleven resistance-trained males performed cycle ergometry to deplete quadriceps muscle glycogen stores, followed by 48 hr of a high (HICHO) or a low (LOCHO) CHO diet. Subjects then performed five sets each of squats, leg presses, and knee extensions (resistance = 15 RM) to failure. Blood samples were taken before and during exercise for determination of glucose and lactate (LA). No differences in performance (repetitions X weight lifted) were observed (HICHO = 15,975±1,381 and LOCHO = 15,723±1,231 kg). Blood glucose was significantly higher after exercise for HICHO compared to LOCHO (HICHO = 4.8 ± 0.2 vs. LOCHO = 3.9 ± 0.2 mmol·L⁻¹). No differences in LA accumulation were observed. The data indicated that preexercise CHO status did not affect resistance exercise performance. Further, the differences in blood glucose and the similarity in LA responses suggest that glycolysis was maintained in the LOCHO condition, and there may have been an increased reliance on blood glucose when preexercise CHO status was low.

Twelve girls who trained in rowing were examined twice a year for 4 years. Their initial age was 11.7 ± (SD) 0.2 yrs. Control groups consisted of 13 girls age 11.5±0.3 yrs and 18 girls age 14.4±0.3 yrs examined simultaneously with trained girls in the first and last year of the study, respectively. The examination involved basic anthropometry, estimation of sexual maturation (Tanner scale), 2-day food records, measurements of resting metabolic rate, energy expenditure following glucose ingestion (50 g), and determinations of blood glucose and plasma insulin concentrations prior to and 2 hrs after glucose load. Body mass, height, and fat content were slightly greater in trained girls. None of the subjects reported disturbances in menstrual function, and the age of menarche was similar for all. Both trained and untrained girls reported similar daily energy intake closer to the lower limit or slightly below the estimates of energy requirements for adolescents. Resting metabolic rate calculated per kg of total body mass or lean body mass was lower in trained girls, while the thermogenic effect of glucose was greater. Plasma insulin concentrations measured 2 hrs after glucose ingestion were lower in trained girls. The results suggest that in circumpubertal girls, increased physical activity leads to energy conservation at rest in postabsorptive state and a tendency toward enhancement of food-induced thermogenesis.

Soccer-associated oxidative stress has barely been studied. The aims of this study were to establish the effect of a soccer training match and the effect of a diet supplementation with a multivitamin complex and coenzyme Q during 3 months of soccer training on the pro-oxidant and antioxidant status of lymphocytes. In a randomized, double-blind trial, 19 male preprofessional soccer players were treated with either an antioxidant nutrient cocktail or placebo for 90 days. After this period the athletes played a soccer match lasting 60 min. All determinations were made under basal conditions before and after the training period and after the match. Basal lymphocyte hydrogen peroxide (H₂O₂) production did not change after the 3 months of training. Catalase activity decreased (about 50%) after the 3 months, whereas glutathione reductase increased its activity (150–200%) both with placebo and in the supplemented group. Basal ascorbate levels were maintained during the training period, whereas α-tocopherol and MDA decreased (about 40%) in both groups. The match increased H₂O₂ production (180%) in both groups when the lymphocytes were stimulated with phorbol myristate acetate, and it also increased MDA levels (150%). Antioxidant enzyme activities and antioxidant vitamin levels were maintained before and after the match. Regular soccer training modifies the lymphocyte strategy to eliminate ROS and increases protection against oxidative damage. A friendly soccer match raises lymphocyte capacity to produce ROS and oxidative damage, but it is not enough to induce a defensive response, thus leading to a situation of postexercise oxidative stress. Supplementation with low doses of antioxidant vitamins and coenzyme Q does not modify the endogenous antioxidant response to training.