Considerations for ultra-endurance activities: part 1- nutrition

ABSTRACT

Ultra-endurance activities (≥ 4h) present unique challenges that, beyond fatigue, may be exacerbated by sub-optimal nutrition during periods of increased requirements and compromised gastrointestinal function. The causes of fatigue during ultra-endurance exercise are multi-factorial. However, mechanisms can potentially include central or peripheral fatigue, thermal stress, dehydration, and/or endogenous glycogen store depletion; of which optimising nutrition and hydration can partially attenuate. If exercise duration is long enough (e.g. ≥ 10h) and exercise intensity low enough (e.g. 45–60% of maximal oxygen uptake), it is bio-energetically plausible that ketogenic adaptation may enhance ultra-endurance performance, but this requires scientific substantiation. Conversely, the scientific literature has consistently demonstrated that daily dietary carbohydrates (3-12g/kg/day) and carbohydrate intake (30-110g/h) during ultra-endurance events can enhance performance at individually tolerable intake rates. Considering gastrointestinal symptoms are common in ultra-endurance activities, effective dietary prevention and management strategies may provide functional, histological, systemic, and symptomatic benefits. Taken together, a well-practiced and individualized fuelling approach is required to optimize performance in ultra-endurance events.

KEYWORDS:

• Energy
• Carbohydrate
• Protein
• Ketogenic
• Gastrointestinal Symptoms
• Epithelium

Acknowledgments

This material is the result of work supported with resources and the use of facilities at the VA Northern California Health Care System, and Monash University, Department of Nutrition Dietetics & Food. The contents reported here do not represent the views of the Department of Veterans Affairs or the United States Government.

Disclosure statement

No potential conflict of interest was reported by the authors.