Nutrition for Ultramarathon Running: Trail, Track, and Road

Abstract

Ultramarathon running events and participation numbers have increased progressively over the past three decades. Besides the exertion of prolonged running with or without a loaded pack, such events are often associated with challenging topography, environmental conditions, acute transient lifestyle discomforts, and/or event-related health complications. These factors create a scenario for greater nutritional needs, while predisposing ultramarathon runners to multiple nutritional intake barriers. The current review aims to explore the physiological and nutritional demands of ultramarathon running and provide general guidance on nutritional requirements for ultramarathon training and competition, including aspects of race nutrition logistics. Research outcomes suggest that daily dietary carbohydrates (up to 12 g·kg−1·day−1) and multiple-transportable carbohydrate intake (∼90 g·hr−1 for running distances ≥3 hr) during exercise support endurance training adaptations and enhance real-time endurance performance. Whether these intake rates are tolerable during ultramarathon competition is questionable from a practical and gastrointestinal perspective. Dietary protocols, such as glycogen manipulation or low-carbohydrate high-fat diets, are currently popular among ultramarathon runners. Despite the latter dietary manipulation showing increased total fat oxidation rates during submaximal exercise, the role in enhancing ultramarathon running performance is currently not supported. Ultramarathon runners may develop varying degrees of both hypohydration and hyperhydration (with accompanying exercise-associated hyponatremia), dependent on event duration, and environmental conditions. To avoid these two extremes, euhydration can generally be maintained through “drinking to thirst.” A well practiced and individualized nutrition strategy is required to optimize training and competition performance in ultramarathon running events, whether they are single stage or multistage.

International Association of Athletics Federations Consensus Statement 2019: Nutrition for Athletics

“…• Well practiced use of evidence-based performance supplements (e.g., caffeine) Ultradistance and mountain running (Costa et al, 2019) >Marathon distance: self-sufficient, semisupported, and full support • Much longer race distances (∼50-250 km than other Athletics events; however, conducted at much lower intensities, across varied terrain and surfaces (i.e., desert, mountain, forest, jungle, arctic)…”

“…Theme 5. Competition Fuel Needs for Longer Events Costa et al, 2019) Most of the power used in long and ultradistance events is provided by oxidative fuel-generating pathways. As CHO is a more economical fuel source than fat (i.e., it produces great amounts of adenosine triphosphate for a given amount of oxygen) and can produce adenosine triphosphate via oxygen-independent pathways, it becomes the dominant fuel source at higher intensities.…”

“…A good tip is to avoid drinking beyond thirst cessation if not aware of individual fluid needs Note. BM = body mass; CHO = carbohydrate Casa et al, 2019;Costa et al, 2019). All strategies should involve a personalized and well-practiced plan that is suited to the specific needs of the events.…”

Defining Off-road Running: A Position Statement from the Ultra Sports Science Foundation

“…Off-road (e. g. unsealed surface and natural environment) running events have become increasingly popular and participation has grown substantially in recent years with many new races appearing around the world [1][2][3][4]. Trail running, for example, as the most popular off-road running sport, has grown considerably from approximately 4.8 million participants in 2009 to 9.1 million in 2017 in the US alone [5].…”

“…For example, ultramarathons, which are defined by a distance longer than the standard marathon distance of 42.195 km, can either take place on tarmac roads (e. g. paved, etc. ), an athletic track, or off-road [2]. An ultramarathon held off-road can be considered trail running, fell running, or skyrunning, depending on the specifics of distance, terrain, and elevation change.…”