Association of gastrointestinal distress in ultramarathoners with race diet.
ABSTRACT Context: Gastrointestinal (GI) distress is common during ultrarunning. Purpose: To determine if race diet is related to GI distress in a 161-km ultramarathon. Methods: Fifteen (10 male, 5 female) consenting runners in the Javelina Jundred (6.5 loops on a desert trail) participated. Body mass was measured immediately prerace and after each loop. Runners reported if they had nausea, vomiting, abdominal cramps, and/or diarrhea after each loop. Subjects were interviewed after each loop to record food, fluid, and electrolyte consumption. Race diets were analyzed using Nutritionist Pro. Results: Nine (8 male, 1 female) of 15 runners experienced GI distress including nausea (89%), abdominal cramps (44%), diarrhea (44%), and vomiting (22%). Fluid consumption rate was higher (p = .001) in runners without GI distress (10.9 ± 3.2 ml · kg-1 · hr-1) than in those with GI distress (5.9 ± 1.6 ml · kg-1 · hr-1). Runners without GI distress consumed a higher percentage fat (p = .03) than runners with GI distress (16.5 ± 2.6 vs. 11.1 ± 5.0). In addition, fat intake rate was higher (p = .01) in runners without GI distress (0.06 ± 0.03 g · kg-1 · hr-1) than in runners with GI distress (0.03 ± 0.01 g · kg-1 · hr-1). Lower fluid and fat intake rates were evident in those developing GI distress before the onset of symptoms. Conclusions: A race diet with higher percentage fat and higher intake rates of fat and fluid may protect ultramarathoners from GI distress. However, these associations do not indicate cause and effect, and factors other than race diet may have contributed to GI distress.
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ABSTRACT: Objectives: Few studies have examined the relationship between physiological variables and ultra-marathon performance. Accordingly, we assessed the physiological parameters of male and female ultra-marathon runners of various talent levels and determined if these parameters were associated with race performance during a 24 h ultra-marathon. Methods: Participants (n=9, maximal oxygen uptake; VO2max =52.86±8.78 ml·kg· -1 ·min -1) with previous ultra-marathon running experience were tested for body fat percentage (BF%), VO2max , ventilatory threshold (VT) and running economy (RE) within one month of competing in a timed ultra-marathon. After completion of the race, Pearson product correlations were run against mean running speed and total distance completed, while gender differences were assessed using an independent t-test. Statistical significance was accepted as p≤0.05. Results: Males had significantly lower BF% and higher VO2max values compared to females. Maximal oxygen uptake (VO2max) was significantly correlated with mean running speed (r=0.78), but not total distance (r=-0.38). Total distance was found to be positively related with RE at both 2.67 (r=0.87, p=0.012) and 3.56 m·s -1 (r=0.81, p=0.026), while no relationship was observed with RE and mean running speed (r≥-0.53). Conclusions: Less efficient runners, defined as those with higher VO2 during the RE trials, covered greater distances over the 24 h race compared to runners with better RE (i.e., lower VO2 during the RE trials). Further, VO2max did not determine total race distance. In closing, a high VO2max may allow runners to maintain faster mean running speeds throughout the race; however numerous other variables such as pacing, nutrition and motivation may limit its ability to be an accurate predictor of 24 h race performance.
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ABSTRACT: Gastrointestinal problems are common, especially in endurance athletes, and often impair performance or subsequent recovery. Generally, studies suggest that 30-50 % of athletes experience such complaints. Most gastrointestinal symptoms during exercise are mild and of no risk to health, but hemorrhagic gastritis, hematochezia, and ischemic bowel can present serious medical challenges. Three main causes of gastrointestinal symptoms have been identified, and these are either physiological, mechanical, or nutritional in nature. During intense exercise, and especially when hypohydrated, mesenteric blood flow is reduced; this is believed to be one of the main contributors to the development of gastrointestinal symptoms. Reduced splanchnic perfusion could result in compromised gut permeability in athletes. However, although evidence exists that this might occur, this has not yet been definitively linked to the prevalence of gastrointestinal symptoms. Nutritional training and appropriate nutrition choices can reduce the risk of gastrointestinal discomfort during exercise by ensuring rapid gastric emptying and the absorption of water and nutrients, and by maintaining adequate perfusion of the splanchnic vasculature. A number of nutritional manipulations have been proposed to minimize gastrointestinal symptoms, including the use of multiple transportable carbohydrates, and potentially the use of nutrients that stimulate the production of nitric oxide in the intestine and thereby improve splanchnic perfusion. However, at this stage, evidence for beneficial effects of such interventions is lacking, and more research needs to be conducted to obtain a better understanding of the etiology of the problems and to improve the recommendations to athletes.05/2014; 44 Suppl 1(Suppl 1):79-85. DOI:10.1007/s40279-014-0153-2This article is viewable in ResearchGate's enriched formatRG Format enables you to read in context with side-by-side figures, citations, and feedback from experts in your field.
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ABSTRACT: An increasing participation in ultra-endurance foot races is cause for greater need to ensure the presence of appropriate medical care at these events. Unique medical challenges result from the extreme physical demands these events place on participants, the often remote settings spanning broad geographical areas, and the potential for extremes in weather conditions and various environmental hazards. Medical issues in these events can adversely affect race performance, and there is the potential for the presentation of life-threatening issues such as exercise-associated hyponatremia, severe altitude illnesses, and major trauma from falls or animal attacks. Organization of a medical support system for ultra-endurance foot races starts with a determination of the level of medical support that is appropriate and feasible for the event. Once that is defined, various legal considerations and organizational issues must be addressed, and medical guidelines and protocols should be developed. While there is no specific or universal standard of medical care for ultra-endurance foot races since a variety of factors determine the level and type of medical services that are appropriate and feasible, the minimum level of services that each event should have in place is a plan for emergency transport of injured or ill participants, pacers, spectators and event personnel to local medical facilities.04/2014; DOI:10.1007/s40279-014-0189-3