include the first-line defense antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase, which act by enzymatically neutralizing oxidants or transforming these to less reactive species and the second-line defense antioxidants such as glutathione (GSH), vitamin C, albumin
Ahmed Ismaeel, Michael Holmes, Evlampia Papoutsi, Lynn Panton and Panagiotis Koutakis
Ina Garthe and Ronald J. Maughan
, categories include sports foods (gels, bars, drinks, protein powders), vitamins and minerals, herbals and botanicals, and ergogenic supplements (Table 1 ). In addition, there is a category which includes supplements for weight loss, products for increased libido, and there are also gluten-free, lactose
Amanda Zaleski, Beth Taylor, Braden Armstrong, Michael Puglisi, Priscilla Clarkson, Stuart Chipkin, Charles Michael White, Paul D. Thompson and Linda S. Pescatello
, CT for the quantitative determination of total serum 25(OH)D via standard electrochemiluminescence binding assay (Elecsys Vitamin D Assay; Roche Diagnostics, Indianapolis, IN). The intra- and interassay coefficients of variation for these analyses were 5.3% and 4.6%, respectively. Resting BP and HR
Souzana K. Papadopoulou, Sophia D. Papadopoulou and George K. Gallos
Adequate nutrition is critically important for the achievement of the adolescent athlete’s optimal performance. The purpose of the present study was to evaluate the adequacy of macro- and micro-nutrients in the adolescent Greek female volleyball players’ diet. The subjects of the study consisted of 16 players who were members of the Junior National Team (NP) and 49 players who participated in the Junior National Championship (CP). Dietary intake was assessed using a 3-day food record. Protein intake (16.0 ± 4.9% of total energy intake) was satisfactory, whereas fat consumption (37.5 ± 11.1%) was above recommended values and at the expense of carbohydrate intake (45.9 ± 12.5%). There were no significant differences between NP and CP concerning the intake of macronutrients, except for the fat intake (when this is expressed in grams per day and grams per kilogram of body weight and the saturated fat intake, which were both higher in NP compared to CP players (p < .05). The mean energy intake was 2013 ± 971 and 1529 ± 675 kcal for NP and CP, respectively (p < .05). NP, in particular, consumed fat and especially saturated fat in order to meet their energy needs. As for micronutrients, the volleyball players fell short of meeting the RDA values for calcium, iron, folk acid, magnesium, zinc, and vitamins A, B1, B2, and B6. There was no difference between NP and CP in micronutrient intake. In conclusion, subjects in the current study lacked proper nutrition in terms of quantity and quality.
Richard R. Suminski, Robert J. Robertson, Fredric L. Goss, Silva Arslanian, Jie Kang, Sergio DaSilva, Alan C. Utter and Kenneth F. Metz
Sixteen men completed four trials at random as follows: (Trial A) performance of a single bout of resistance exercise preceded by placebo ingestion (vitamin C); (Trial B) ingestion of 1,500 mg L-arginine and 1,500 mg L-lysine, immediately followed by exercise as in Trial A; (Trial C) ingestion of amino acids as in Trial B and no exercise; (Trial D) placebo ingestion and no exercise. Growth hormone (GH) concentrations were higher at 30,60, and 90 min during the exercise trials (A and B) compared with the resting trials (C and D) (p < .05). No differences were noted in [GH] between the exercise trials. [GH] was significantly elevated during resting conditions 60 min after amino acid ingestion compared with the placebo trial. It was concluded that ingestion of 1,500 mg arginine and 1,500 mg ly sine immediately before resistance exercise does not alter exercise-induced changes in [GH] in young men. However, when the same amino acid mixture is ingested under basal conditions, the acute secretion of GH is increased.
G.W. Davison, C.M. Hughes and R.A. Bell
The purpose of this investigation was to determine the effects of antioxidant supplementation on DNA damage following exercise. Fourteen subjects were randomly assigned to one of two groups and required to ingest either antioxidants (400 mg α-lipoic acid, 200 mg co-enzyme Q10, 12 mg manganese, 600 mg vitamin C, 800 mg N-acetyl cysteine, 400 μg selenium, and 400 IU α-tocopherol per day) or placebos for 7 d. Exercise increased DNA damage, PS, FRAP, and LDH (P < 0.05), but not selectively between groups. LDH and PS concentration decreased 1 h post-exercise (P < 0.05), while LH concentration decreased 1 h post-exercise in the antioxidant group only (P < 0.05). The antioxidant group had a higher concentration of LH (P < 0.05), perhaps due to a selective difference between groups post-exercise (P < 0.05). The main findings of this investigation demonstrate that exhaustive aerobic exercise induces DNA damage, while anti-oxidant supplementation does not protect against damage.
Allan H. Goldfarb, Changmo Cho, Hojune Cho, Brett Romano-Ely and M. Kent Todd
The purpose of this study was to determine whether an isocaloric beverage with added protein and vitamins (CHOPA) would influence oxidative stress and inflammation after cycling to exhaustion as indicated by plasma protein carbonyls (PC), lipid hydroperoxides (LOOH), and interleukin-6 (IL-6). Twelve trained men (18–33 yr) volunteered and performed this randomized crossover study. Participants cycled at 70% VO2peak until fatigue and at 80% VO2peak 22–24 hr later to fatigue with either carbohydrate or CHOPA. Blood collected before the cycling at rest and 24, 48, and 72 hr after the exercise was analyzed for PC and LOOH spectrophotometrically and for IL-6 via an enzyme-linked immunosorbent assay. The data were analyzed with SPSS using repeated-measures ANOVA. PC demonstrated significant treatment (p = .037) and time (p = .004) effects with no Treatment × Time interaction. PC was higher in the CHOPA treatment than with CHO independent of time and increased at 24 (48%), 48 (59%), and 72 (67%) hr after exercise compared with preexercise values. Resting LOOH and IL-6 did not have any significant changes with time or treatment. These data indicate that an isocaloric CHOPA drink after 2 cycling bouts to exhaustion will exacerbate the resting PC level compared with an isocaloric drink, with no influence on plasma LOOH or IL-6. In addition, a modest significant increase in PC over time independent of treatment occurred, which suggests a mild oxidative stress in the days after exhaustive exercise.
Edith M. Peters and Jeni M. Goetzsche
Training (T) and prerace (PR) dietary intakes of male and female athletes participating in a 90-km ultramarathon and the usual diets of matched, sedentary controls were investigated using 24-hr dietary records. Supplement use, mean weekly training distance, and race performance times were recorded. Macro- and micronutrient intakes were analyzed using computerized nutritional analysis programs. Total mean energy intake in the T and PR diets of the runners was 10.1 and 12.8 MJ in the men (n = 150) and 7.5 and 9.1 MJ in the women (n = 23). Mean relative contribution of CHO to the runners' total kilojoule intake increased from 50.0 and 49.5% in the T diets to 57.7 (p < .05; n = 153) and 56.4% (p < .05; n = 23) in the PR diets of male and female runners, respectively, and energy-boosting supplements were included in the PR diets of 48% of female and 59% of male runners. Seventy-eightpercent of female and 62% of male runners used vitamin and mineral supplements in their T diets as opposed to 39% of female and 28% of male controls. No statistically significant relationship was found between total kilojoule, CHO, fat, protein, and selected micronutrient intake during the 3 days before the race and performance in the 90-km event in runners of homogenous training status and gender.
Jongkyu Kim, Seung-ki Kang, Han-sang Jung, Yoon-suck Chun, Jennifer Trilk and Seung Ho Jung
Athletes report frequent use of various dietary supplements (DSs). However, no study has examined DS use and antidoping knowledge in Korean Olympians. The objectives of this study were to obtain information about Korean Olympians’ DS use during the training period for the Beijing 2008 Summer Olympic Games and immediately before their Olympic events, to obtain DS-intake reasons and DS providers, and to obtain information on athletes’ doping education, knowledge, and educators. Korean Olympians completed 2 questionnaires 1 wk before the opening and within 1 wk after the closing of the Beijing 2008 Summer Olympic Games. Results showed that 79% of male and 82% of female Olympians take more than 1 DS during the training period and that vitamins and Oriental supplements are the 2 top-ranked DSs. Reasons for DS use were to improve recovery ability (66%) and muscle performance (22%), and sources of obtaining DSs were parents (36%) and coaches (35%). Furthermore, 79% of Korean Olympians reported receiving regular education on antidoping regulations from Olympic-sponsored education classes (64%) and coaches (15%). In conclusion, this study was the first to examine DS use and antidoping-related information in Korean Olympians. Because some herbal products contain substances banned by the World Anti-Doping Agency, athletes should be cautious in using mixed Oriental supplements.
Angela de Silva, Yasas Samarasinghe, Dhammika Senanayake and Pulani Lanerolle
Intake of dietary supplements is widespread among athletes in developed countries. This study evaluated the use of dietary supplements in athletes from a developing country. Dietary supplementation practices of 113 national-level athletes age 15–35 yr in Sri Lanka were assessed. All athletes from track-and-field, badminton, football, swimming, cycling, and karate squads who consented to participate in the study were administered an anonymous questionnaire by an interviewer. Information on number of supplements taken, frequency of use, nature of product, rationale, sources of advice, and reasons for taking supplements was obtained. Most athletes (94%) consumed dietary supplements. On average, 3.7 products/day were consumed. Footballers had significantly lower intake of supplements than other athletes (footballers 71%, others 98%; p < .05). They also consumed fewer products per day (footballers 0.7, others 3.5; p < .05). Popular supplements included multivitamins, vitamin E, calcium, energy foods and drinks, and creatine. Multiple supplement use was common, with 29% athletes taking 4 products/day. The athletes sought advice on supplement use from sports doctors (45%), team coaches (40%), or friends (15%). Most took supplements to improve performance (79%), and 19% claimed to take supplements to improve their overall health status. Dietary supplement use is widespread among national-level Sri Lankan athletes. The ad hoc use of supplements indicates that educational intervention in the sporting community is essential.