This study determined the effect of training on body composition, dietary intake, and iron status of eumenorrheic female collegiate swimmers (n = 18) and divers (n = 6) preseason and after 16 wk of training. Athletes trained on dryland (resistance, strength, fexibility) 3 d/wk, 1.5 h/d and in-water 6 d/wk, nine, 2-h sessions per week (6400 to 10,000 kJ/d). Body-mass index (kg/m2; P = 0.05), waist and hip circumferences (P ≤ 0.0001), whole body fat mass (P = 0.0002), and percentage body fat (P ≤ 0.0001) decreased, whereas lean mass increased (P = 0.028). Using dual-energy X-ray absorptiometry, we found no change in regional lean mass, but fat decreased at the waist (P = 0.0002), hip (P = 0.0002), and thigh (P = 0.002). Energy intake (10,061 ± 3617 kJ/d) did not change, but dietary quality improved with training, as refected by increased intakes of fber (P = 0.036), iron (P = 0.015), vitamin C (P = 0.029), vitamin B-6 (P = 0.032), and fruit (P = 0.003). Iron status improved as refected by slight increases in hemoglobin (P = 0.046) and hematocrit (P = 0.014) and decreases in serum transferrin receptor (P ≤ 0.0001). Studies are needed to further evaluate body composition and iron status in relation to dietary intake in female swimmers.
Heidi L. Petersen, C. Ted Peterson, Manju B. Reddy, Kathy B. Hanson, James H. Swain, Rick L. Sharp and D. Lee Alekel
Susan M. Kleiner, Terry L. Bazzarre and Barbara E. Ainsworth
The nutritional status of 11 female and 13 male elite bodybuilders at the first drug-tested USA Championship was examined through food records kept by subjects. Diets were repetitive and monotonous, and average daily energy and protein contents were relatively similar for men and women. Percent calories from protein, fat, and carbohydrate were 39%, 12%, and 48% for females, and 40%, 11%, and 49% for males, respectively. Females consumed 0% vitamin D, 52% calcium, 76% zinc (as percents of RDA) and below the Estimated Safe and Adequate Dietary Allowance amounts for copper and chromium. Males consumed 46% of vitamin D RDA. Although dietary magnesium intakes were above the RDA, serum magnesium levels in females were below reference values, which should be investigated. Serum zinc levels were high in men and women. Eighty-one percent of females reported recurrent contest-related amenorrhea for 2 ± 1 months precontest. Dietary intakes of men were adequate but the restrictive intakes of women may place them at risk for calcium, copper, and chromium deficiencies.
Veronica A. Mullins, Linda B. Houtkooper, Wanda H. Howell, Scott B. Going and C. Harmon Brown
This study describes the body composition, dietary nutrient intake, dietary practices, and biochemical indices of iron status of elite female American heptathletes during training. Four-day diet records and dietary practice questionnaires were obtained from 19 female heptathletes (26 ± 3 years) during the training season. Anthropometric measurements and fasting blood samples were obtained at the lowest phase of the training cycle. These athletes had a low body fat (13.8 ± 2.7%) and high fat-free mass to height ratios (33.0 ± 2.0 kg/m). Average nutrient intakes were > 67% of the reference intakes for all nutrients except vitamin E. Most dietary nutrient densities were higher than NHANES III nutrient densities for women 20–29 years old. More than 50% of the athletes took vitamin supplements and monitored their hydration status. Fifteen of the 17 athletes reported a normal menstrual cycle. Markers of biochemical iron status were all within the normal range. On average, these athletes were lean with high levels of fat free mass, adequate nutrient intakes, and normal biochemical indices of iron status. However, individual data reveals considerable variability within this group.
Sakuko Ishizaki, Takako Koshimizu, Kae Yanagisawa, Yoshiko Akiyama, Yuko Mekada, Nobuhiro Shiozawa, Noriko Takahaski, Jun Yamakawa and Yukari Kawano
This study was to assess the effect of a fixed dietary intake on biomarkers of red blood cell (RBC) biosynthesis and degradation. Over a two-year period, eight collegiate rhythmic gymnasts participated in this study. During the first year, they ate self-selected diets. During the second year, a fixed dietary intake involving consumption of common Japanese foods containing 15 mg iron and 1500 kcal energy was maintained for 4 wk at the beginning of the program. Fixed dietary intakes resulted in significantly increased intakes of protein, minerals and vitamins, and significantly decreased fat intake, but total energy and carbohydrate intakes were unchanged. Mean values of RBC, Hb, Ht, or TIBC were not affected by the intervention. A fixed dietary intervention appeared to enhance RBC turnover by increasing the capacity for erythrocyte biosynthesis and degradation, although the prevalence of iron-deficiency anemia remained unchanged.
Athletes use a variety of nutritional ergogenic aids to enhance performance. Most nutritional aids can be categorized as a potential energy source, an anabolic enhancer, a cellular component, or a recovery aid. Studies have consistently shown that carbohydrates consumed immediately before or after exercise enhance performance by increasing glycogen stores and delaying fatigue. Protein and amino acid supplementation may serve an anabolic role by optimizing body composition crucial in strength-related sports. Dietary antioxidants, such as vitamins C and E and carotenes, may prevent oxidative stress that occurs with intense exercise. Performance during high-intensity exercise, such as sprinting, may be improved with short-term creatine loading, and high-effort exercise lasting 1-7 min may be improved through bicarbonate loading immediately prior to activity. Caffeine dosing before exercise delays fatigue and may enhance performance of high-intensity exercise.
Ian P. Snider, Terry L. Bazzarre, Scott D. Murdoch and Allan Goldfarb
This study examined the effects of the Coenzyme Athletic Performance System (CAPS) on endurance performance to exhaustion. CAPS contains 100 mg coenzyme Q10,500 mg cytochrome C, 100 mg inosine, and 200 IU vitamin E. Eleven highly trained male triathletes were given three daily doses of either CAPS or placebo (dicalcium phosphate) for two 4-week periods using a double-blind crossover design. A 4-week washout period separated the two treatment periods. An exhaustive performance test, consisting of 90 minutes of running on a treadmill (70%
Katsumi Sugiura, Izumi Suzuki and Kando Kobayashi
Mean daily intakes of energy and nutrients were surveyed from 3-day food records for 62 elite Japanese track-and-field athletes (28 males and 34 females) selected to participate in the 1994 Asian Championship games held in Hiroshima, Japan. Mean energy intakes of male and female athletes were 3,141 kcal (±592) and 2,508 kcal (±537), respectively. Based on the Japanese Recommended Dietary Allowances (JRDAs), long-distance and middle-distance runners had significantly higher energy and macronutrient intakes than did sprinters, jumpers, and throwers. There was no significant difference in micronutrient intake among the different types of athletes. However, of the sprinters, jumpers, and throwers. 15 males (54%) and 22 females (65%) consumed less than the JRDA for at least one micronutrient (i.e., vitamin or mineral). For some athletes, nutritional counseling that provides strategies for increasing food intake is recommended to optimize nutrient intake.
Dietary intakes of 24 female athletes in various sports were compared inseason and postseason to those reported by 24 nonathletes during the same time period. Diets were analyzed for energy, carbohydrate, fat, protein, vitamins A and C, thiamin, riboflavin, niacin, folacin, calcium, and iron. During the study, the athletes' and nonathletes' diets were similar. Their energy intakes were lower than recommended while their iron and calcium intakes were marginal (less than 70% of the recommended dietary allowance). Although few dietary changes were observed, the nonathletes' diets changed more than those of the athletes during the study. Both groups reduced their energy intakes but only the nonathletes' reduction was significant. Initially many subjects were dieting. More subjects reported dieting during the second recording period. These results suggest that the desire to be thin may influence dietary intakes of female athletes more than changes in exercise training.
P. Farajian, S.A. Kavouras, M. Yannakoulia and L.S. Sidossis
To investigate whether aquatic athletes follow optimal dietary intake, 58 athletes, all members of the Greek national swimming and water polo teams, were tested. Dietary intake was assessed at the nutrient, food, and food group level using the 24-h recall method and a food frequency questionnaire. Mean energy intake for males and females was 14.3 and 8.5 MJ, respectively. Mean carbohydrate consumption for male and female athletes was 4.5 g/kg and 3.8 g/kg of body weight, respectively. Fat intake was 153 g for males and 79 g for females. A significant number of the athletes (71% of the males, 93% of the females) did not meet the Dietary Reference Intakes for at least one of the antioxidant vitamins. The data suggest that athletes of both genders consumed too much fat and too little carbohydrate. Insufficient fruit and vegetable intake was related to low intake of antioxidants.
Lothar Rokitzki, Enno Logemann, Georg Huber, Elfriede Keck and Josef Keul
This study was undertaken to evaluate the effects of 5 months of α-tocopherol supplementation on physical performance during aerobic exercise training in 30 top-class cyclists. Antioxidative effects of supplementation were also studied. Plasma α-tocopherol concentration increased significantly in the vitamin E-supplemented group, whereas the placebo group showed a trend toward decrease. Physical performance did not improve in the α-tocopherol-supplemented group compared to the placebo group. Heart rates were also not significantly different. Lactate concentrations at the aerobic threshold and the anaerobic threshold were identical. Thus, there was no performance improvement in the α-tocopherol-supplemented group. However there was a significant reduction in CK in serum of the E-supplemented group. A trend toward decrease in GOT, GPT, and LDH was observed with α-tocopherol supplementation. Moreover, significantly reduced malondialdehyde serum levels were measured in the E-supplemented group. The findings indicate a protective effect of α-tocopherol supplementation against oxidative stress induced by strenuous exercise.