Open-water swimming (OWS) is a rapidly developing discipline. Events of 5–25 km are featured at FINA World Championships, and the international circuit includes races of 5–88 km. The Olympic OWS event, introduced in 2008, is contested over 10 km. Differing venues present changing environmental conditions, including water and ambient temperatures, humidity, solar radiation, and unpredictable tides. Furthermore, the duration of most OWS events (1–6 hr) creates unique physiological challenges to thermoregulation, hydration status, and muscle fuel stores. Current nutrition recommendations for open-water training and competition are either an extension of recommendations from pool swimming or are extrapolated from other athletic populations with similar physiological requirements. Competition nutrition should focus on optimizing prerace hydration and glycogen stores. Although swimmers should rely on self-supplied fuel and fluid sources for shorter events, for races of 10 km or greater, fluid and fuel replacement can occur from feeding pontoons when tactically appropriate. Over the longer races, feeding pontoons should be used to achieve desirable targets of up to 90 g/hr of carbohydrates from multitransportable sources. Exposure to variable water and ambient temperatures will play a significant role in determining race nutrition strategies. For example, in extreme environments, thermoregulation may be assisted by manipulating the temperature of the ingested fluids. Swimmers are encouraged to work with nutrition experts to develop effective and efficient strategies that enhance performance through appropriate in-competition nutrition.
Gregory Shaw, Anu Koivisto, David Gerrard and Louise M. Burke
Ken Hodge, Elaine A. Hargreaves, David Gerrard and Chris Lonsdale
We examined whether constructs outlined in self-determination theory (Deci & Ryan, 2002), namely, autonomy-supportive and controlling motivational climates and autonomous and controlled motivation, were related to attitudes toward performance-enhancing drugs (PEDs) in sport and drug-taking susceptibility. We also investigated moral disengagement as a potential mediator. We surveyed a sample of 224 competitive athletes (59% female; M age = 20.3 years; M = 10.2 years of experience participating in their sport), including 81 elite athletes. Using structural equation modeling analyses, our hypothesis proposing positive relationships with controlling climates, controlled motivation, and PEDs attitudes and susceptibility was largely supported, whereas our hypothesis proposing negative relationships among autonomous climate, autonomous motivation, and PEDs attitudes and susceptibility was not supported. Moral disengagement was a strong predictor of positive attitudes toward PEDs, which, in turn, was a strong predictor of PEDs susceptibility. These findings are discussed from both motivational and moral disengagement viewpoints.
Gordon Sleivert, Val Burke, Craig Palmer, Alan Walmsley, David Gerrard, Stephen Haines and Roger Littlejohn
To determine the effects of deer antler velvet on maximal aerobic performance and the trainability of muscular strength and endurance, 38 active males were randomly assigned in a double-blind fashion to either deer antler velvet extract (n = 12), powder (n = 13), or placebo groups (n = 13). Subjects were tested prior to beginning supplementation and a 10-week strength program, and immediately post-training. All subjects were measured for circulating levels of testosterone, insulin-like growth factor, erythropoietin, red cell mass, plasma volume, and total blood volume. Additionally, muscular strength, endurance, and VO2max were determined. All groups improved 6 RM strength equivalently (41 ± 26%, p < .001), but there was a greater increase in isokinetic knee extensor strength (30 ± 21% vs. 13 ± 15%, p = .04) and endurance (21 ± 19% vs. 7 ± 12%, p = .02) in the powder compared to placebo group. There were no endocrine, red cell mass or VO2max changes in any group. These findings do not support an erythropoetic or aerobic ergogenic effect of deer antler velvet. Further, the inconsistent findings regarding the effects of deer antler velvet powder supplementation on the development of strength suggests that further work is required to test the robustness of the observation that this supplement enhances the strength training response and to ensure this observation is not a type I error.