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Dietary Supplement Usage, Motivation, and Education in Young Canadian Athletes

Kristin Wiens, Kelly Anne Erdman, Megan Stadnyk, and Jill A. Parnell

Purpose:

To evaluate dietary supplement use in young Canadian athletes, their motivation for consuming supplements, and their sources of information.

Methods:

A questionnaire tested for content validity and reliability was administered to 567 athletes between the ages of 11 and 25 years from the Canadian athletic community in face-to-face meetings. Demographics and sport variables were analyzed using descriptive statistics. Fisher’s exact tests were used to examine dietary supplementation patterns and sources of information regarding dietary supplement use between categories of gender, age, sport type, and competition level.

Results:

Ninety-eight percent of athletes were taking at least one dietary supplement. Males were more likely to consume protein powder, energy drinks, recovery drinks, branched chain amino acids, beta-alanine, and glutamine (p < .01); supplements typically associated with increased muscle mass. Athletes 11–17 years old focused on vitamin and mineral supplements; whereas, athletes 18–25 years old focused on purported ergogenic supplements. Strength training athletes were more likely to consume creatine, glutamine, and protein powders (p < .02). Reasons for supplement use included to stay healthy, increase energy, immune system, recovery, and overall performance. Primary sources of information were family and friends, coaches, and athletic trainers; with 48% of athletes having met with a dietitian. Preferred means of education included individual consultations, presentations, and the internet.

Conclusions:

The majority of young athletes are using dietary supplements with the belief they will improve performance and health; however, may not always have reliable information. Educational programs using individual consultations and electronic media are recommended for this demographic.

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Amino Acids and the Brain: Do They Play a Role in “Central Fatigue”?

Romain Meeusen and Phil Watson

It is clear that the cause of fatigue is complex, infuenced by both events occurring in the periphery and the central nervous system (CNS). It has been suggested that exercise-induced changes in serotonin (5-HT), dopamine (DA), and noradrenaline (NA) concentrations contribute to the onset of fatigue during prolonged exercise. Serotonin has been linked to fatigue because of its documented role in sleep, feelings of lethargy and drowsiness, and loss of motivation, whereas increased DA and NA neurotransmission favors feelings of motivation, arousal, and reward. 5-HT has been shown to increase during acute exercise in running rats and to remain high at the point of fatigue. DA release is also elevated during exercise but appears to fall at exhaustion, a response that may be important in the fatigue process. The rates of 5-HT and DA/NA synthesis largely depend on the peripheral availability of the amino acids tryptophan (TRP) and tyrosine (TYR), with increased brain delivery increasing serotonergic and DA/NA activity, respectively. TRP, TYR, and the branched-chained amino acids (BCAAs) use the same transporter to pass through the blood-brain barrier, meaning that the plasma concentration ratio of these amino acids is thought to be a very important marker of neurotransmitter synthesis. Pharmacological manipulation of these neurotransmitter systems has provided support for an important role of the CNS in the development of fatigue. Work conducted over the last 20 y has focused on the possibility that manipulation of neurotransmitter precursors may delay the onset of fatigue. Although there is evidence that BCAA (to limit 5-HT synthesis) and TYR (to elevate brain DA/NA) ingestion can influence perceived exertion and some measures of mental performance, the results of several apparently well-controlled laboratory studies have yet to demonstrate a clear positive effect on exercise capacity or performance. There is good evidence that brain neurotransmitters can play a role in the development of fatigue during prolonged exercise, but nutritional manipulation of these systems through the provision of amino acids has proven largely unsuccessful.

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Influence of Beverage Temperature on Exercise Performance in the Heat: A Systematic Review

Catriona A. Burdon, Helen T. O’Connor, Janelle A. Gifford, and Susan M. Shirreffs

Purpose:

Increased core temperature (Tc), impaired cardiovascular function, and dehydration contribute to fatigue during prolonged exercise in the heat. Although many studies have examined mechanisms addressing these factors, few have investigated the effect of cold beverage temperature on thermoregulation and exercise performance in the heat.

Methods:

Citations from MEDLINE (Ovid), Sport Discus (EBSCOhost), AUSPORT and AusportMed (Informit), Web of Science, and SCOPUS were identified from the earliest record until September 2008 using the search terms drink temperature, beverage temperature, fluid temperature, water temperature, and cold fluid combined with body temperature and thermoregulation. To be included, studies needed to assess core or rectal temperature during exercise in moderate or hot environmental conditions. After quality rating was completed by two reviewers, the difference in mean Tc and exercise performance was calculated.

Results:

Ten studies meeting search inclusion criteria were available for analysis. Three were excluded because sufficient detail or statistical data were not reported. A meta-analysis was not performed because the studies were deemed too different to group. Three of the remaining 7 studies found modulated Tc with cold beverage consumption, and from the 4 that conducted exercise performance tests, performance improved by 10% with cold fluids.

Conclusion:

Cold fluid may attenuate Tc rise and improve exercise performance in the heat; however, study findings are mixed. Research using well-trained athletes and fluid-ingestion protocols replicating competition scenarios is required. Potential sensory effects of cold fluid in maintaining motivation also need to be assessed as a mechanism underpinning improved performance.

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Effect of Whey Protein Hydrolysate on Performance and Recovery of Top-Class Orienteering Runners

Mette Hansen, Jens Bangsbo, Jørgen Jensen, Bo Martin Bibby, and Klavs Madsen

This trial aimed to examine the effect of whey protein hydrolysate intake before and after exercise sessions on endurance performance and recovery in elite orienteers during a training camp. Eighteen elite orienteers participated in a randomized controlled intervention trial during a 1-week training camp (13 exercise sessions). Half of the runners (PRO-CHO) ingested a protein drink before (0.3 g kg−1) and a protein-carbohydrate drink after (0.3 g protein kg−1 and 1 g carbohydrate kg−1) each exercise session. The others ingested energy and timematched carbohydrate drinks (CHO). A 4-km run-test with 20 control points was performed before and on the last day of the intervention. Blood and saliva were obtained in the mornings, before and after run-tests, and after the last training session. During the intervention, questionnaires were fulfilled regarding psychological sense of performance capacity and motivation. PRO-CHO and not CHO improved performance in the 4-km run-test (interaction p < .05). An increase in serum creatine kinase was observed during the week, which was greater in CHO than PRO-CHO (interactionp < .01). Lactate dehydrogenase (p < .001) and cortisol (p = .057) increased during the week, but the change did not differ between groups. Reduction in sense of performance capacity during the intervention was greater in CHO (p < .05) than PRO-CHO. In conclusion, ingestion of whey protein hydrolysate before and after each exercise session improves performance and reduces markers of muscle damage during a strenuous 1-week training camp. The results indicate that protein supplementation in conjunction with each exercise session facilitates the recovery from strenuous training in elite orienteers.

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Fasting Before Evening Exercise Reduces Net Energy Intake and Increases Fat Oxidation, but Impairs Performance in Healthy Males and Females

Tommy Slater, William J.A. Mode, Mollie G. Pinkney, John Hough, Ruth M. James, Craig Sale, Lewis J. James, and David J. Clayton

- and fasted-state exercise commencing in the morning or early evening, indicating fasted exercise may reduce daily energy intake, irrespective of the time of day. The amount of exercise performed and motivation to exercise are, however, important to maximize both the energy deficit achieved and the

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Using Contemporary Behavior Change Science to Design and Implement an Effective Nutritional Intervention Within Professional Rugby League

Nessan Costello, Jim McKenna, Louise Sutton, Kevin Deighton, and Ben Jones

the wheel incorporates a model of behavior known as the capability, opportunity, motivation, and behavior model (COM-B; Michie et al., 2011 ), which identifies the sources of behavior that are important for intervention. It states that an individual requires capability, opportunity, and motivation to

Open access

International Olympic Committee Expert Group Statement on Dietary Supplements in Athletes

International Olympic Committee Expert Group on Dietary Supplements in Athletes

with Olympic and highly competitive athletes know that the pressures of elite sport and the substantial rewards that follow success provide a high level of motivation to adopt any safe and legal strategy that might promise even the smallest performance gain. Dietary supplements operate in this space

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Athletes and Supplements: Prevalence and Perspectives

Ina Garthe and Ronald J. Maughan

Many athletes, at all levels of competition, place great emphasis on the use of dietary supplements, but of all the factors that determine athletic performance, supplements can play only a very small role. Compared with factors such as talent, training, tactics, and motivation, nutrition has a

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Case Study: Dose Response of Caffeine on 20-km Handcycling Time Trial Performance in a Paratriathlete

Terri Graham-Paulson, Claudio Perret, and Victoria Goosey-Tolfrey

. Well-trained/elite athletes are also likely to have greater motivation to perform maximal exercise ( Burke, 2008 ). The current case study provided a unique opportunity to investigate the effects of CAF in an elite paratriathlete. Presentation of the Sporting Issue At the London 2012 Paralympic Games

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Quinine Ingestion During the Latter Stages of a 3,000-m Time Trial Fails to Improve Cycling Performance

Naroa Etxebarria, Brad Clark, Megan L. Ross, Timothy Hui, Roland Goecke, Ben Rattray, and Louise M. Burke

parabolic pace strategy, where the pace is high in the first phase of the TT, moderated during the middle phase, and increased toward the end ( Foster et al., 2004 ). The brain is thought to control pace through the integration of determinants, including motivation, knowledge of the endpoint, prior