International Society of Sports Nutrition Position Stand: Nutritional recommendations for single-stage ultra-marathon; training and racing

Background. In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~60% of energy intake, 5 – 8 g⸱kg−1·d−1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~1.6 g·kg−1·d−1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g⸱kg−1·d−1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150 - 400 kcal⸱h−1 (carbohydrate, 30 – 50 g⸱h−1; protein, 5 – 10 g⸱h−1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450 – 750 mL⸱h−1 (~150 – 250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., >575 mg·L−1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety

Do male 100-km ultra-marathoners overdrink?

Incidences of EAH in 100 km ultra-marathoners were lower compared with reports on marathoners. Body mass decreased, plasma volume increased, and plasma [Na+] was maintained. Since fluid intake was related neither to Δ plasma volume nor to Δ plasma [Na+], we assume that factors other than fluid intake maintained body fluid homeostasis

Triathlon and Ultra-Endurance Events in Tropical Environments

International audiencePhysical performance in tropical environments, which combine heat and high humidity, is a challenge that requires specific preparation. The high humidity of a tropical climate alters thermoregulatory capacity by limiting the rate of sweat evaporation. Proper management of wholebody temperature is thus essential to complete an endurance event like a long-distance triathlon or an ultramarathon in such an environment. In triathlon and ultra-endurance races, which can last from 8 to 20 h, performance in tropical settings is closely linked to the capacity to maintain hydration status. Indeed, the rate of withdrawal in these longer events has been associated with water intake, with many finishers showing alterations in electrolyte (e.g. sodium) balance. To counterbalance the impact of a tropical climate and maintain performance, several countermeasures can be adopted, such as using hydration and cooling strategies, and heat acclimation

Hydration in sport and exercise

Hypohydration, defined as a deficit in total body water that exceeds normal daily fluid fluctuations, is typically set as a fluid loss equivalent to >2% of body mass. The evaporation of sweat provides the principle means of heat dissipation during exercise in the heat; typical sweat rates of 300–2000 mL/h during sporting activities are generally not matched by fluid intake, leading to hypohydration. Although there are shortcomings in the literature related to hypohydration and sports performance, it is likely that some scenarios (hot conditions, larger fluid losses and prolonged aerobic exercise) are more at risk of incurring impaired performance. Guidelines for fluid intake during exercise and sporting activity are contentious since they need to span situations in which it is easy to overdrink compared with sweat losses and others in which significant levels of hypohydration occur. Nevertheless, athletes can be guided to develop fluid intake plans that are suited to their specific needs