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
Gary Slater, Benedict Tan and Kong Chuan Teh
The supplementation practices of elite athletes in Singapore were studied using an anonymous questionnaire. Information was sought on not only the type of supplements used but also dosage, rationale for use, and other factors that might influence supplement use including selected demographic parameters and sources of information relating to supplements. Data was collected from 160 athletes across a spectrum of 30 sports. Use of supplements was widespread, with 77% of respondents acknowledging use of at least 1 product. Respondents ingested a total of 59 different supplements, with each athlete using on average 3.6 ± 0.3 different products. Sports drinks, caffeine, vitamin C, multivitamin/mineral supplements, and essence of chicken were some of the most commonly ingested products, confirming that while vitamin/mineral supplements are popular, sports supplements and traditional/herbal preparations were also well accepted. Respondents preferred to source information pertaining to supplements from “significant others” and other readily accessible sources. A small number of respondents acknowledged the use of International Olympic Committee (IOC) banned or restricted substances, highlighting the need for athletes to consult sports medicine professionals with specialist knowledge of dietary supplements in advance of initiating any supplementation regime.
Anni Heikkinen, Antti Alaranta, Ilkka Helenius and Tommi Vasankari
The aim of this study was to evaluate the frequency of dietary supplement (DS) use among elite Finnish athletes in 2002 and 2009. In 2009, the authors also wanted to examine the reasons for athletes’ DS use, whether athletes feel they have experienced benefits from their supplement use, and whether athletes had had an opportunity to consult dietary specialists. Cross-sectional studies were conducted in 2002 and 2009 among Finnish Olympic athletes. Data were collected using semistructured questionnaires, mainly in national team camps. The study population in 2002 was 446 athletes, and in 2009 it was 372. The number of DS users was high in both study years (81% in 2002 and 73% in 2009). Vitamin D consumption was low in both 2002 and 2009 (0.7% and 2.0%, respectively). An increase was found in consumption of omega-3 fatty acids between study years (11% in 2002 and 19% in 2009; p = .002), and their regular use nearly doubled (8% and 15%, p = .002). For vitamin and mineral users, the main reason for DS use was to prevent nutritional deficiencies, and for nutritional supplement users the main reason was recovery from exercise. Only 27% of all athletes and 30% of DS users had an opportunity to consult dietary specialists in 2009. This survey shows that supplementation rates among elite Finnish athletes are high and there may be over- and underuse of some micronutrient supplements. There is a need for professional nutritional counseling among national elite athletes.
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.
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.
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.
Jacqueline R. Berning, John P. Troup, Peter J. VanHandel, Jack Daniels and Nancy Daniels
Dietary food records from adolescent male and female swimmers participating in a national developmental training camp were analyzed for nutrient density. The mean caloric intake was 5,221.6 kcal for males and 3,572.6 kcal for females. The distribution of calories between carbohydrates, protein, and fat was not ideal for athletes trying to optimize performance. These young swimmers consumed too much fat and not enough carbohydrate. They consumed more than the RDA of vitamins A and C, and thiamine, riboflavin, and niacin; however, some concern is expressed for females who did not meet the RDA for calcium and iron. This study shows that although a group of adolescent swimmers may be consuming enough nutrients, individual swimmers may have very poor dietary habits and thus may not be providing adequate fuel or nutrients for optimal training or performance.
Eleni Michopoulou, Alexandra Avloniti, Antonios Kambas, Diamanda Leontsini, Maria Michalopoulou, Symeon Tournis and Ioannis G. Fatouros
This study determined dietary intake and energy balance of elite premenarcheal rhythmic gymnasts during their preseason training. Forty rhythmic gymnasts and 40 sedentary age-matched females (10–12 yrs) participated in the study. Anthropometric profile and skeletal ages were determined. Dietary intake and physical activity were assessed to estimate daily energy intake, daily energy expenditure, and resting metabolic rate. Groups demonstrated comparable height, bone age, pubertal development, resting metabolic rate. Gymnasts had lower body mass, BMI, body fat than age-matched controls. Although groups demonstrated comparable daily energy intake, gymnasts exhibited a higher daily energy expenditure resulting in a daily energy deficit. Gymnasts also had higher carbohydrate intake but lower fat and calcium intake. Both groups were below the recommended dietary allowances for fiber, water, calcium, phosphorus and vitamin intake. Gymnasts may need to raise their daily energy intake to avoid the energy deficit during periods of intense training.
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%
Jerry A. Frentsos and Janine T. Baer
Dietary habits were evaluated in 6 elite triathletes (4 male, 2 female). Analysis of 7-day diet records showed mean daily energy and carbohydrate intake to be insufficient to support estimated requirements. Mean intakes of vitamins and most minerals exceeded the Recommended Dietary Allowances (RDAs) except zinc and chromium, which did not meet 66% of recommended amounts. Individualized nutrition intervention using the Diabetic Food Exchange System to support performance during training and competition was provided. To improve dietary intake, subjects consumed fortified nutrition supplements (Reliv, Inc.) before and after daily training. Follow-up 7-day diet records showed that average energy intake and percentage of energy from carbohydrate increased, as did intakes of zinc and chromium. Triathletes' performance in a short course triathlon was improved compared to a similar competition completed prior to the nutrition intervention. Following the intervention, triathletes were able to meet recommended daily energy, macronutrient, and micronutrient intakes and improve endurance performance.