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Cited by 164Muscle metabolism and nutritionSports Performance and TrainingThermoregulation and physiological responses

International Society of Sports Nutrition Position Stand: nutritional considerations for single-stage ultra-marathon training and racing

Open access
Tiller, Nicholas B., Roberts, Justin D., Beasley, Liam, Chapman, Shaun, Pinto, Jorge M., Smith, Lee, Wiffin, Melanie, Russell, Mark +17 more·2019·Journal of the International Society of Sports Nutrition
DOI 10.1186/s12970-019-0312-9PMC PMC6839090
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Abstract

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.

AI snapshot

Written from the paper’s full text.

TL;DR

This ISSN Position Stand reviews nutritional considerations for single-stage ultra-marathon training and racing and provides evidence-graded recommendations. It emphasizes periodized carbohydrate intake, adequate protein, individualized hydration/electrolyte strategies, GI-distress management, and limited support for ketogenic/ketone/MCT/vitamin supplements except caffeine.

Key findings

  • For training, the paper recommends a moderate-to-high carbohydrate diet (~60% of energy intake, 5–8 g·kg⁻¹·d⁻¹), protein intakes of ~1.6 g·kg⁻¹·d⁻¹, with up to 2.5 g·kg⁻¹·d⁻¹ during demanding training; strategic carbohydrate moderation may enhance fat oxidation but caution is advised against chronic glycogen depletion.
  • For racing, runners should aim to consume 150–400 Kcal·h⁻¹ (carbohydrate 30–50 g·h⁻¹; protein 5–10 g·h⁻¹), fluid volumes of 450–750 mL·h⁻¹ (~150–250 mL every 20 min), and sodium concentrations greater than most commercial products (>575 mg·L⁻¹; 500–700 mg·L⁻¹ suggested).
  • GI distress is common: a conservative estimate is 30–50% of ultra-marathon athletes, with values of 70–80% reported; in a 100-mile race cohort (n=272), 96% experienced GI symptoms and 44% reported GI issues negatively impacted performance.
  • Evidence for ketogenic diets, ketone esters, MCTs, vitamins/minerals, and L-glutamine is limited or insufficient for ultra-marathon performance; caffeine is supported for later race stages, and NSAIDs are discouraged.

Methods

  • Position Stand/objective critical review; articles searched via PubMed, MEDLINE, and Google Scholar using combinations of terms including extreme-endurance, hydration, marathon, nutrition, pathophysiology, physiology, supplements, ultra-marathon, and ultra-endurance, with manual reference-list searching.
  • All relevant published studies were included irrespective of methodological concerns (e.g., low sample sizes, short durations, lack of randomization/control, biases), and evidence statements were graded using an adapted NHLBI system with a fourth case-report level.
  • Focus was single-stage ultra-marathon events up to and including 152 miles (245 km), with recommendations based on empirical studies, field data, and estimated energy/macronutrient requirements.

Limitations

  • Stated: data informing recommendations are incomplete, particularly relative to other sports, due to relatively low participant numbers, athlete reluctance to volunteer for invasive/time-consuming testing, and remote/extreme race locations that limit complex or invasive data collection.
  • Stated: included studies had methodological concerns such as low sample sizes, short study durations, lack of randomization, lack of control measures, and other biases; many recommendations are category B/C/D, and further research is warranted for ketogenic diets, ketone esters, MCTs, vitamins, L-glutamine, and probiotics.
  • Evident: this is a Position Stand rather than a systematic review with meta-analysis, and several recommendations extrapolate from non-ultra-marathon endurance contexts or from small surveys/example food tables (e.g., Table 4 based on n=12).

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1186/s12970-019-0312-9

Cites

207 of 207 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 242 cited sources checked · 0 supported · 0 flagged

  • Findingreasoning

    Differences among athletes with respect to training duration, pace, and body mass lead to a range of caloric requirements from ~38-63 Kcal·kg−1·d−1.

    “However, differences among athletes with respect to training duration, pace, and body mass, will lead to a range of caloric requirements (for both males and females) from ~ 38–63 Kcal·kg− 1 d− 1.”
    Quote in the paperSubstantial claim
  • Findingcitation

    Post-exercise urine output decreases as the drink sodium concentration increases.

    “Unequivocally, post-exercise urine output decreases as the drink sodium concentration increases”
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    • cites [82] Nose H, 1988, J Appl Physiol (1985) source

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  • Findingcitation

    Greater fluid volumes up to 200% body mass loss may only lead to greater post-exercise hydration when consumed with higher concentrations of sodium (61 mmol·L−1; 1403 mg·L−1).

    “Greater fluid volumes up to 200% body mass loss may only lead to greater post-exercise hydration when consumed with higher concentrations of sodium (61 mmol·L− 1; 1403 mg·L− 1) [80]”
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    • cites [80] source

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  • Findingcitation

    A low-sodium drink consumed at a volume of 150% of exercise-induced body mass loss resulted in enhanced hydration relative to an identical concentration consumed at 100% body mass loss.

    “Shirreffs et al. [80] and Mitchell et al. [81], who reported that a low-sodium drink consumed at a volume of 150% of exercise-induced body mass loss resulted in enhanced hydration relative to an identical concentration consumed at 100% body mass loss.”
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    • cites [80] source

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    • cites [81] source

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  • Findingcitation

    Over longer training distances (marathon), high-level runners exhibited a body weight loss of 0.3% and 1.7% in cool and warm conditions, respectively, even when consuming fluid at 1 L·h−1.

    “Over longer training distances (marathon), high-level runners exhibited a body weight loss of 0.3 and 1.7%, in cool and warm conditions, respectively, even when consuming fluid at a rate of 1 L·h− 1 [78].”
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    • cites [78] Cheuvront SN, 2007, Sports Med source

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    Findingcitation

    The sodium content of commercial sports drinks (~20-25 mmol·L−1; 460-575 mg·L−1) is lower than that typically lost in sweat and should be considered a conservative target.

    “The sodium content of commercial sports drinks (~20–25 mmol·L− 1; 460–575 mg·L− 1) is lower than that typically lost in sweat [83, 84] and should, therefore, be considered a conservative target.”
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    • cites [83] source

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    • cites [84] source

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    Findingcitation

    Average plasma osmolality was found to be similar between groups of low-volume (1.2 L·d−1) and high-volume (2-4 L·d−1) drinkers, and it is possible to attain euhydration with a range of fluid intakes.

    “average plasma osmolality was found to be similar between groups of low-volume (1.2 L·d− 1) and high-volume (2–4 L·d− 1) drinkers [8]; it is possible, therefore, to attain euhydration with a range of fluid intakes.”
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    • cites [8] source

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    Findingcitation

    Over the half-marathon distance, mean sweat losses of ~1.4 L were observed in male runners and, when offset against fluid ingestion during exercise, resulted in net fluid losses of ~0.3 L.

    “Over the half-marathon distance (13.1 miles), mean sweat losses of ~1.4 L were observed in male runners and, when offset against fluid ingestion during exercise, resulted in net fluid losses of ~ 0.3 L [77].”
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    • cites [77] Pereira ER, 2017, J Sports Med Phys Fitness source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingcitation

    Only an estimated 20% of endurance runners monitor their hydration status.

    “Only an estimated 20% of endurance runners monitor their hydration status [90].”
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    • cites [90] source

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    Findingcitation

    In 213 runners contesting one of three race distances (44, 67, or 112 km), mean energy intake was 183 Kcal·h−1, with no discernible difference among race distances.

    “In 213 runners contesting one-of-three race distances (44, 67, or 112 km; Ultra Mallorca Serra de Tramuntana; Spain), mean energy intake was 183 Kcal·h− 1, with no discernible difference among race distances [95].”
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    • cites [95] source

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    Findingcitation

    Finishers of a 100-mile (161 km) race had a significantly greater protein intake relative to non-finishers (131.2 ± 79.0 versus 43.0 ± 56.7 g), and when expressed as a relative ratio per hour, race finishers consumed twice the quantity (0.08 versus 0.04 g·kg−1·h−1).

    “Indeed, finishers of a 100-mile (161 km) race had a significantly greater protein intake relative to non-finishers (131.2 ± 79.0 versus 43.0 ± 56.7 g) and, when expressed as a relative ratio per hour, race finishers consumed twice the quantity (0.08 versus 0.04 g·kg− 1·h− 1) [15].”
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    • cites [15] source

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    Findingcitation

    Laboratory data demonstrate that respiratory exchange ratio (RER) gradually decreases until the 8th hour of a 24 h treadmill run, and plateaus thereafter, reflecting a reduced rate of energy derived from carbohydrate and congruent with a diminished running velocity.

    “Laboratory data demonstrate that respiratory exchange ratio (RER) gradually decreases until the 8th hour of a 24 h treadmill run, and plateaus thereafter, reflecting a reduced rate of energy derived from CHO; moreover, this is congruent with a diminished running velocity [99].”
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    • cites [99] source

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    Findingcitation

    Throughout a 100-mile race, finishers consumed a total of 98.1 ± 53.0 g of fat, approximately 5-fold greater than non-finishers (19.4 ± 21.1 g); normalized for body mass and running velocity, this equated to a rate of fat ingestion three times greater in finishers (0.06 ± 0.03 versus 0.02 ± 0.02 g·kg−1·h−1).

    “Throughout a 100-mile race, finishers consumed a total of 98.1 ± 53.0 g of fat, which was approximately 5-fold greater than that of non-finishers (19.4 ± 21.1 g); moreover, when normalized for body mass and running velocity, this equated to a rate of fat ingestion that was three times greater in finishers (0.06 ± 0.03 versus 0.02 ± 0.02 g·kg− 1·h− 1 [15]).”
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    • cites [15] source

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    Findingcitation

    The urine color chart is the most common means of estimating hydration status in runners.

    “The urine color chart is the most common means of estimating hydration status in runners [90].”
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    • cites [90] source

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    Findingcitation

    As muscle glycogen diminishes, there is a compensatory increase in fat oxidation, with rates of 0.2-0.5 g·min−1 typically observed during endurance exercise.

    “As muscle glycogen diminishes, there is a compensatory increase in fat oxidation, with rates of 0.2–0.5 g·min− 1 typically observed during endurance exercise [100]”
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    • cites [100] source

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  • May combine two claims.

    Findingnone given

    A 50 kg athlete undertaking a 50 mile (80 km) race at 8.0 km·h−1 (~10 h) will expend ~3460 Kcal, and a 70 kg athlete would expend ~4845 Kcal (an approximate range of 346-484 Kcal·h−1).

    “First, consider that a 50 kg athlete undertaking a 50 mile (80 km) race at 8.0 km·h− 1 (~ 10 h) will expend ~ 3460 Kcal. For the same event contested at the same pace, a 70 kg athlete would expend ~ 4845 Kcal (an approximate Kcal range of 346–484 Kcal·h− 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    A 50 kg athlete undertaking a 100 mile (161 km) ultra-marathon at an average pace of 6.5 km·h−1 may expend ~6922 Kcal in ~25 h, whereas a 70 kg athlete would likely expend ~9891 Kcal (range of 277-395 Kcal·h−1).

    “Second, a 50 kg athlete undertaking a 100 mile (161 km) ultra-marathon at an average pace of 6.5 km·h− 1 may expend ~ 6922 Kcal in ~ 25 h, whereas at the same pace, a 70 kg athlete would likely expend ~ 9891 Kcal (range of 277–395 Kcal·h− 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    The earliest reported cases of hyponatraemia were observed in ultra-marathon runners and Ironman triathletes, and the athletes most commonly developing symptomatic hyponatremia typically participate in distance running events of >26.2 miles (>42.2 km).

    “Although the condition is rare, and individual susceptibility plays a role in prevalence, the earliest reported cases were observed in ultra-marathon runners and Ironman triathletes [9] (i.e., during ultra-endurance exercise), and the athletes most commonly developing symptomatic hyponatremia typically participate in distance running events of > 26.2 miles (> 42.2 km) [126].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9] Hew-Butler T, Loi V, Pani A, Rosner M. Exercise-associated hyponatremia: 2017 update. Frontiers in Medicine. 2017;4(21):1. source

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    • cites [126] source

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  • May combine two claims.

    Premisecitation

    Ultra-marathon racing places a heavy dependence on oxidative metabolism to utilize glycogen and fat stores efficiently, and with increasing race distance there is a substantial increase in the use of free fatty acids as fuel.

    “From a metabolic perspective, ultra-marathon racing places a heavy dependence on oxidative metabolism to utilize glycogen and fat stores efficiently; moreover, with increasing race distance, there is a substantial increase in the use of free fatty acids as fuel [25].”
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    • cites [25] source

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    Premisecitation

    Exercising while chronically glycogen-depleted increases circulating stress hormones (e.g., cortisol) and causes disturbances in several indices of immune function, thereby increasing susceptibility to overtraining.

    “Conversely, exercising while chronically glycogen-depleted increases circulating stress hormones (e.g., cortisol), and causes disturbances in several indices of immune function (e.g., circulating leukocytes) [6] thereby increasing susceptibility to overtraining.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [6] Gleeson M, 1998, Int J Sport Nutr source

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  • Classified as probably not a substantial claim.

    Premisecitation

    Athletes are cautioned against training in a chronically depleted state, especially during intensive training periods or when repeated days of prolonged training are scheduled, as this may lead to low energy availability and ultimately relative energy deficiency (RED-S).

    “As such, athletes are cautioned against training in a chronically depleted state (especially during intensive training periods, or when repeated days of prolonged training are scheduled) as this may lead to low energy availability and, ultimately, relative energy deficiency (RED-S [46];).”
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    • cites [46] source

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    Premisecitation

    Creatine kinase concentrations of 274 ± 71 U·L−1 were observed post-marathon, relative to 2983 ± 1716 U·L−1 following a 100 km race, and 4970 ± 2222 U·L−1 after a 308 km race.

    “Specifically, creatine kinase concentrations of 274 ± 71 U·L− 1 were observed post-marathon, relative to 2983 ± 1716 U·L− 1 following a 100 km race, and 4970 ± 2222 U·L− 1 after a 308 km race [58].”
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    • cites [58] source

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  • May combine two claims.

    Premisecitation

    Available data support the contention that while ketogenic approaches may enhance fuel utilization to favor fat oxidation, the ability to perform at higher intensities may be compromised, or even reduced, due to downregulation of pyruvate dehydrogenase, leading to reduced oxygen economy.

    “Finally, available data support the contention that while ketogenic approaches may enhance fuel utilization to favor fat oxidation, the ability to perform at higher intensities may be compromised, or even reduced, due to downregulation of pyruvate dehydrogenase [54], leading to reduced oxygen economy [55].”
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    • cites [54] source

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    • cites [55] source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Based on nitrogen-balance methodology, protein intakes of >1.6 g·kg−1·d−1 have been recommended for endurance athletes who have high training demands.

    “Based on nitrogen-balance methodology, protein intakes of > 1.6 g·kg− 1·d− 1 have been recommended for endurance athletes who have high training demands [35].”
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    • cites [35] source

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  • May combine two claims.

    Premisecitation

    Exercising while glycogen-depleted increases circulating cortisol and causes disturbances in several indices of immune function, and post-exercise immune dysfunction is most pronounced following prolonged, continuous exercise (>1.5 h) performed without food.

    “Exercising while glycogen-depleted increases circulating cortisol and causes disturbances in several indices of immune function (including plasma glutamine and circulating leukocytes) [6], and post-exercise immune dysfunction is most pronounced following prolonged, continuous exercise (> 1.5 h) performed without food [47].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [6] Gleeson M, 1998, Int J Sport Nutr source

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    • cites [47] source

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  • May combine two claims.

    Premisecitation

    Downhill running is associated with greater peak flexion angles relative to level or uphill running, which exaggerates the eccentric component of impact-loading, thereby increasing muscle damage.

    “Downhill running (on mountainous or undulating paths) is associated with greater peak flexion angles relative to level or uphill running; this exaggerates the eccentric component of impact-loading, thereby increasing muscle damage [56].”
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    • cites [56] source

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  • May combine two claims.

    Premisecitation

    Pre-exercise CHO intake facilitates the uptake of blood glucose into muscle and suppresses hepatic glycogenolysis, which may increase the potential risk of hypoglycaemia during the early period of a training session in susceptible individuals.

    “Pre-exercise CHO intake also facilitates the uptake of blood glucose into muscle, and suppresses hepatic (liver) glycogenolysis [37], which may increase the potential risk of hypoglycaemia during the early period of a training session in susceptible individuals [38]”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [37] Magkos F, 2010, Nutrition source

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    • cites [38] source

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  • May combine two claims.

    Interpretationcitation

    Race distance and/or duration mediate muscle damage more than race intensity, although duration is not the sole determinant of muscle damage during ultra-marathon.

    “These data suggest that race distance and/or duration mediate muscle damage more than race intensity, although duration is not the sole determinant of muscle damage during ultra-marathon [60].”
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    • cites [60] source

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  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Unless strategically targeting a ketogenic approach, fat intakes ranging from 1.0-1.5 g·kg−1·d−1 are likely sufficient, although heavier/faster individuals may need fat intakes close to 2.0 g·kg−1·d−1 to support caloric needs.

    “Unless strategically targeting a ketogenic approach, fat intakes ranging from 1.0–1.5 g·kg− 1·d− 1 are likely sufficient, although heavier/faster individuals may need fat intakes close to 2.0 g·kg− 1·d− 1 to support caloric needs.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A macronutrient distribution of 60% CHO, 15% protein, and 25% fat is typically recommended to support repeated bouts of endurance training.

    “With respect to total energy intake, a macronutrient distribution of 60% CHO, 15% protein, and 25% fat is typically recommended to support repeated bouts of endurance training [32].”
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    • cites [32] source

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  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Caution is advised against training chronically glycogen depleted, particularly during periods of repeated high-intensity exercise or prior to racing.

    “However, caution is advised against training chronically glycogen depleted, particularly during periods of repeated high-intensity exercise or prior to racing.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    For athletes with greater caloric requirements, relative protein intakes up to 2.5 g·kg−1·d−1 may be warranted.

    “However, for athletes with greater caloric requirements, relative protein intakes up to 2.5 g·kg− 1·d− 1 may be warranted.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    For runners with greater training mileage and/or pace, carbohydrate intakes ranging from 7 to 10 g·kg−1·d−1 may be warranted, pending metabolic flexibility.

    “For runners with greater training mileage and/or pace, carbohydrate intakes ranging from 7 to 10 g kg− 1·d− 1 may be warranted, pending the athlete’s metabolic flexibility (i.e., their individual capacity to readily switch between fat or CHO oxidation at high absolute work-loads [34])”
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    • cites [34] source

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  • May combine two claims.

    Premisecitation

    Chronic dehydration can influence health outcomes, with dehydration-mediated changes in vasopressin and markers of metabolic dysfunction or disease.

    “chronic dehydration can influence health outcomes, with several authors noting dehydration-mediated changes in vasopressin, and markers of metabolic dysfunction or disease [8].”
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    • cites [8] source

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  • May combine two claims.

    Interpretationnone given

    Protein intakes of ~1.6-2.1 g·kg−1·d−1 are sufficient to optimally stimulate muscle protein synthesis and will likely support recovery from training.

    “Protein intakes of ~ 1.6–2.1 g·kg− 1·d− 1 are sufficient to optimally simulate muscle protein synthesis, which will likely support recovery from training.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Overuse of fluids that contain insufficient concentrations of electrolytes may cause overhydration, decreased electrolyte concentrations, an increased risk of dilutional hyponatremia, and/or failure of the renal system in extreme cases.

    “overuse of fluids that contain insufficient concentrations of electrolytes (e.g., water or hypotonic sports drinks) may cause overhydration, decreased electrolyte concentrations, an increased risk of dilutional hyponatremia, and/or failure of the renal system [89] in extreme cases.”
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    • cites [89] source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Drinking-to-thirst is appropriate for responding to daily hydration needs.

    “it is reasonable to suggest that drinking-to-thirst is appropriate for responding to daily hydration needs.”
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    • cites [79] source

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  • May combine two claims.

    Premisecitation

    The actual fluid intake necessary to attain euhydration on a day-to-day basis varies with renal and extrarenal water losses, and absolute daily fluid intake from food and drink varies widely among individuals.

    “The actual fluid intake necessary to attain euhydration on a day-to-day basis will vary with renal and extrarenal water losses [85]; moreover, the absolute daily fluid intake (from food and drink) will vary widely among individuals.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [85] source

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  • May combine two claims.

    Premisecitation

    A 20 g bolus of whey protein appears sufficient to maximize fractional synthetic rate after resistance exercise, with up to 30 g appropriate for larger athletes (>85 kg).

    “A 20 g bolus of whey protein appears sufficient to maximize fractional synthetic rate after resistance exercise [66], with up to 30 g appropriate for larger athletes (>85 kg).”
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    • cites [66] source

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    Premisecitation

    Amounts exceeding 2.1 g·kg−1·d−1 are unlikely to have additive effects on muscle protein synthesis, although the protein contribution to energy metabolism may be greater in ultra-marathon runners engaged in very high-mileage training.

    “Furthermore, amounts exceeding 2.1 g·kg− 1·d− 1 are unlikely to have additive effects on muscle protein synthesis, although the protein contribution to energy metabolism (and other structural/functional processes) may be greater in ultra-marathon runners engaged in very high-mileage training. This may, in turn, necessitate slightly higher intakes [64].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [64] Cintineo HP, 2018, Front Nutr source

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  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The mechanistic link between glycogen depletion in skeletal muscle and liver and a subsequent early-onset fatigue during prolonged exercise was made in the 1960s.

    “The mechanistic link between glycogen depletion in skeletal muscle and liver, and a subsequent early-onset fatigue during prolonged exercise was made in the 1960s [98].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [98] Bergstrom J, 1966, Nature source

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  • Classified as probably not a substantial claim.

    Interpretationreasoning

    After key training sessions, at least 460 mg·L−1 of sodium should be ingested, either in food or as a supplement.

    “Simultaneously, at least 460 mg·L− 1 of sodium should be ingested, either in food or as a supplement.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Foods with a greater fat content often contain more sodium, which may help mitigate the risk of exercise-associated hyponatraemia.

    “Moreover, foods with a greater fat content (see Table 4) often contain more sodium, which may help mitigate the risk of exercise-associated hyponatraemia.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    A carbohydrate target of 90 g·h−1 would necessitate a race diet almost exclusively comprising carbohydrate (360 Kcal·h−1), which is typically unsustainable given the greater preference for fat and salt that manifest in longer races.

    “Worthy of consideration is that a CHO target of 90 g·h− 1 would necessitate a race diet almost exclusively comprising CHO (360 Kcal·h− 1) which is typically unsustainable given the greater preference for fat and salt that manifest in longer races.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationnone given

    It is plausible that protein ingested during an ultra-marathon would mitigate the ill-effects of muscle damage and/or positively influence energy metabolism.

    “Nevertheless, it is plausible that protein ingested during an ultra-marathon would mitigate the ill-effects of muscle damage and/or positively influence energy metabolism.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Current literature advocates carbohydrate ingestion rates up to ~90 g·h−1 for events >120 min, particularly when using multiple transportable carbohydrates containing glucose and fructose.

    “Although current literature advocates CHO ingestion rates up to ~ 90 g·h− 1 for events > 120 min, particularly when using ‘multiple transportable carbohydrates’ containing glucose and fructose [104]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [104] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    This rate of carbohydrate ingestion may lead to nutrient malabsorption and gastrointestinal distress.

    “Moreover, this rate of ingestion may lead to nutrient malabsorption and GI distress [105].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [105] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    A lower average work rate permits a faster rate of gastric emptying, which tends to be compromised only at exercise intensities >70% maximal oxygen uptake (V̇O2max).

    “A nuance of the longer distance event is that the lower average work rate permits a faster rate of gastric emptying, which tends to be compromised only at exercise intensities > 70% maximal oxygen uptake (V̇O2max) [93].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [93] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Venn diagram proposed by Cheuvront and Sawka is a more sophisticated tool appropriate for healthy, active, low-risk populations which estimates hydration status by combining measures of nude body mass, thirst perception, and urine color.

    “The Venn diagram proposed by Cheuvront and Sawka [91] is a more sophisticated tool (appropriate for healthy, active, low-risk populations) which estimates hydration status by combining measures of nude body mass, thirst perception, and urine color.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [91] Cheuvront SN, Sawka MN: Hydration assessment of athletes. [https://www.gssiweb.org/sports-science-exchange/article/sse-97-hydration-assessment-of-athletes].

      Not checked in the free run.

  • May combine two claims.

    Interpretationnone given

    The reduction in plasma glucose concentration that follows glycogen depletion is associated with acute cognitive decline, which can compromise athlete safety on ultra-marathon courses of technical terrain or those requiring navigation.

    “In addition to negatively impacting endurance performance, the reduction in plasma glucose concentration that follows glycogen depletion is associated with acute cognitive decline; this, in turn, can compromise athlete safety on ultra-marathon courses of technical terrain or those requiring navigation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Foods with a greater fat content are advantageous during racing in terms of caloric provision per unit of weight, which is pertinent for minimizing pack weight when running self-sufficient.

    “Foods with a greater fat content are advantageous during racing in terms of caloric provision per unit of weight, and this is pertinent for minimizing pack weight when running self-sufficient.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Dehydration results in diminished exercise capacity and an increased risk of heat illness and rhabdomyolysis.

    “The result is a diminished exercise capacity [118], and an increased risk of heat illness and rhabdomyolysis [118].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [118] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    It is feasible that the role of BCAAs in offsetting central fatigue may be further pronounced during the extreme-distance ultra-marathons.

    “It is feasible that the role of BCAAs in offsetting central fatigue may be further pronounced during the extreme-distance ultra-marathons, the conditions of which are rarely replicated, and difficult to perform reliably, in a laboratory environment.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Insufficient fluid replacement results in a net loss of body water, the main consequence of which is dehydration-induced cardiovascular drift; i.e., a reduction in plasma volume and a necessary increase in heart rate to maintain cardiac output.

    “Insufficient fluid replacement, therefore, results in a net loss of body water, the main consequence of which is dehydration-induced cardiovascular drift; i.e., a reduction in plasma volume and a necessary increase in heart rate to maintain cardiac output [117].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [117] Coyle EF, 1998, Int J Sports Med source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Modest symptoms of hyponatraemia include headache, fatigue, and nausea, but it can result in seizures and death in severe cases.

    “Modest symptoms include headache, fatigue, and nausea, but can result in seizures and death in severe cases [9].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [9] Hew-Butler T, Loi V, Pani A, Rosner M. Exercise-associated hyponatremia: 2017 update. Frontiers in Medicine. 2017;4(21):1. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Runners tended to exhibit a penchant for savory food in the latter stages of ultra-marathon, supporting the notion that changes in food preference may reflect nutrient inadequacies resulting from long-duration activity.

    “In the aforementioned studies, runners tended to exhibit a penchant for savory food (i.e., flavoursome, non-sweet, and containing greater relative amounts of fat and salt) in the latter stages of ultra-marathon, thereby supporting the notion that changes in food preference may reflect nutrient inadequacies resulting from long-duration activity.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [115] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Dehydration may diminish cognitive performance and increase perceived exertion.

    “Dehydration may also diminish cognitive performance [11, 118] and increase perceived exertion [119].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [11] source

      Not checked in the free run.

    • cites [118] source

      Not checked in the free run.

    • cites [119] James LJ, 2017, Phys Rep

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationcitation

    To reduce the risk of hyponatremia during long-duration exercise, runners should consume sodium in concentrations of 500-700 mg·L−1 of fluid.

    “In order to reduce the risk of hyponatremia during long-duration exercise, runners should consume sodium in concentrations of 500–700 mg·L− 1 of fluid [118].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [118] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S1 (asserted). May combine two claims.

    Interpretationcitation

    Increasing the circulating concentrations of BCAAs might mitigate 5-HT accumulation, attenuate the serotonin:dopamine ratio, and potentially offset central fatigue.

    “with the hypothesis that increasing the circulating concentrations of BCAAs might mitigate 5-HT accumulation, attenuate the seretonin:dopamine ratio [110], and potentially offset central fatigue.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [110] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Over-hydration, and the consequent dilution of plasma sodium, can have severe adverse effects on health, and there are case-reports of water intoxication in runners who aggressively rehydrate.

    “Over-hydration, and the consequent dilution of plasma sodium, can have severe adverse effects on health (see Exercise-associated hyponatraemia), and there are case-reports of water intoxication in runners who aggressively rehydrate [124].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [124] Siegel AJ, 2015, Am J Med source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Prolonged exercise increases the synthesis and metabolism of 5-hydroxytryptamine (5-HT; serotonin) in the brain, which is associated with lethargy, drowsiness, and reduced motivation.

    “Prolonged exercise increases the synthesis and metabolism of 5-hydroxytryptamine (5-HT; serotonin) in the brain, which is associated with lethargy, drowsiness, and reduced motivation [108].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [108] Meeusen R, 2007, Int J Sport Nutr Exerc Metab source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    The equivocal findings on protein during ultra-marathon may result from the co-ingestion of protein and carbohydrate, and/or differences in the exercise modality used between studies.

    “As such, the equivocal findings may result from the co-ingestion of protein and CHO, and/or differences in the exercise modality used between studies.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Slightly greater amounts of sodium and other electrolytes will be required in hot (e.g., >25 °C / 77 °F) and/or humid (e.g., >60%) conditions when sweat rates are elevated; in such conditions, runners should target ~300-600 mg·h−1 of sodium (1000-2000 mg of NaCl).

    “Slightly greater amounts of sodium (and other electrolytes) will be required in hot (e.g., > 25 °C / 77 °F) and/or humid (e.g., > 60%) conditions when sweat rates are elevated; in such conditions, runners should target ~ 300–600 mg·h− 1 of sodium (1000–2000 mg of NaCl).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Calorie deficits during racing are expected but can be minimized by consuming 150-400 Kcal·h−1, pending differences in body mass, race distance/pace, and individual gut tolerance.

    “Calorie deficits during racing are expected but can be minimized by consuming 150–400 Kcal·h− 1, pending differences in body mass, race distance/pace, and individual gut tolerance.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Calories should be consumed from a combination of protein (5-10 g·h−1), carbohydrate (30-50 g·h−1), and fat; however, foods with greater fat content may be preferred in longer races.

    “Calories should be consumed from a combination of protein (5–10 g·h− 1), CHO (30–50 g·h− 1), and fat; however, foods with greater fat content may be preferred in longer races.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The available data suggest that there are broad individual intakes among ultra-marathon runners, but that successful runners tend to meet the lower-limits of recommended values.

    “Collectively, the available data suggest that there are broad individual intakes among ultra-marathon runners, but that successful runners tend to meet the lower-limits of recommended values.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Interpretationcitation

    If consumed in fluid, sodium concentrations greater than ~1000 mg·L−1 (50 mmol·L−1) should be avoided as this may reduce drink palatability.

    “If consumed in fluid, sodium concentrations greater than ~ 1000 mg·L− 1 (50 mmol·L− 1) should be avoided as this may reduce drink palatability [127].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [127] Baker LB, 2014, Compr Physiol source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Sodium is the major ion of the extracellular fluid and contributes to the generation of action potentials for muscle contraction, and it also has an important role in fluid retention.

    “Sodium is the major ion of the extracellular fluid and contributes to the generation of action potentials for muscle contraction, but it also has an important role in fluid retention [118].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [118] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The inclusion of dietary prebiotic nutrients may play an important role in short-chain fatty acid production, which may support epithelial integrity.

    “The inclusion of dietary prebiotic nutrients (e.g., fructooligosaccharides, inulin, pectin) may also play an important role in short-chain fatty acid production, which may support epithelial integrity (for review, see [149]).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [149] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Many ultra-marathon runners rarely rely solely on sports drinks for energy and/or CHO intake during racing.

    “Although many ultra-marathon runners rarely rely solely on sports drinks for energy and/or CHO intake during racing, use of solutions with multiple transportable carbohydrates may be an effective short-term strategy to limit the likelihood of non-completion due to energy under-consumption.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The use of multiple transportable carbohydrate solutions has been shown in trained individuals to increase overall intestinal absorption, facilitate increased total CHO oxidation rates, and limit gut discomfort typically observed with single CHO solutions.

    “The use of ‘multiple transportable carbohydrate’ solutions (i.e., those containing glucose, fructose, and/or maltodextrin) has been shown in trained individuals to increase overall intestinal absorption, facilitate increased total CHO oxidation rates, and limit the degree of gut discomfort typically observed with single CHO solutions (e.g., fructose) [104, 140].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [104] source

      Not checked in the free run.

    • cites [140] Roberts JD, 2014, J Int Soc Sports Nutr source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Ultra-marathon training may elicit physiological adaptations including increased intestinal tight-junction integrity and enhanced immunological response to endotoxin release.

    “While ultra-marathon training may elicit progressive behavioral changes (e.g., greater confidence in trialing personalized nutrition strategies) and physiological adaptations (e.g., increased intestinal tight-junction integrity and enhanced immunological response to endotoxin release [135]), targeted nutrition strategies may confer a degree of individual benefit.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [135] Brock-Utne JG, 1988, S Afr Med J

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Nausea was cited as the most common symptom likely to affect race strategy, reported in 60% of athletes.

    “Nausea was cited as the most common symptom likely to affect race strategy (reported in 60% of athletes) [130], perhaps due to the subsequent impact on the ability to ingest food and fluid.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [130] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Symptoms pertaining to exercise-associated GI distress are highly individualized and may be related to predisposition, intestinal microbiome activity, and feeding tolerance.

    “Symptoms pertaining to exercise-associated GI distress are highly individualized and may be related to predisposition, intestinal microbiome activity (based on bacterial quantity and species diversity), and feeding tolerance [137].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [137] source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    High rates of CHO ingestion, although beneficial for race completion, might actually exacerbate symptoms of GI distress.

    “This supports the notion that high rates of CHO ingestion, although being beneficial for race completion, might actually exacerbate symptoms of GI distress.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Repeat doses of 50 mg·h−1 caffeine are likely to be well-tolerated during prolonged ultra-marathon.

    “Although there are no specific guidelines pertaining to caffeine intake during prolonged ultra-marathon, repeat doses of 50 mg·h− 1 are likely to be well-tolerated, principally reserved for night-running when circadian rhythms are likely to be affected.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisenone given

    Symptoms of upper-GI distress, particularly nausea, are commonly reported during ultra-marathons, are a cause of non-completion, and are more prevalent in longer races.

    “Symptoms of upper-GI distress, particularly nausea, are commonly reported during ultra-marathons, are a cause of non-completion, and are more prevalent in longer races.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Consumption rates of multivitamins/vitamin C as high as ~70% have been reported in small cohorts.

    “However, in a report on the supplement habits of 20 ultra-marathon runners, 30% of respondents reported taking multivitamins, and 20% reported taking vitamin C before races [169], although consumption rates as high as ~ 70% have been reported in small cohorts [170].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [170] Singh A, 1993, Med Sci Sports Exerc source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Within 60 min of ingestion, a 500 mg·kg−1 ketone ester increased beta-hydroxybutyrate concentrations to levels associated with nutritional ketosis (~3 mmol·L−1) and increased intramuscular fat oxidation even with replete glycogen stores or co-ingested CHO.

    “Within 60 min of ingestion, a 500 mg·kg− 1 ketone ester increased beta-hydroxybutyrate (D-βHB) concentrations to levels associated with nutritional ketosis (~ 3 mmol·L− 1), and increased intramuscular fat oxidation even in the presence of replete glycogen stores or when co-ingested with CHO [50, 164].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [50] source

      Not checked in the free run.

    • cites [164] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    L-glutamine supplementation may be associated with heat-shock factor-1 expression, providing a mechanistic link to GI integrity via regulation of occludin tight-junction proteins.

    “It has been proposed elsewhere that L-glutamine supplementation may be associated with heat-shock factor-1 (HSF-1) expression, providing a mechanistic link to GI integrity via regulation of occludin tight-junction proteins [178].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [178] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The dose response of caffeine is not linear; larger caffeine doses do not necessarily confer greater performance.

    “However, the dose response is not linear (i.e., larger caffeine doses do not necessarily confer greater performance), and moderate rates of ingestion are likely sufficient to optimize ergogenic gains [159].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [159] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Caffeine blocks adenosine receptors in the brain and inhibits the binding of adenosine, resulting in improved cognitive function and concentration.

    “Caffeine works via two potential mechanisms: firstly, there is a centrally-mediated ergogenic effect, whereby caffeine blocks adenosine receptors in the brain and inhibits the binding of adenosine, resulting in improved cognitive function and concentration; secondly, caffeine potentiates intramuscular calcium release, thereby facilitating excitation-contraction coupling to increase muscle contract”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [154] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In a report on 20 ultra-marathon runners, 30% reported taking multivitamins and 20% reported taking vitamin C before races.

    “However, in a report on the supplement habits of 20 ultra-marathon runners, 30% of respondents reported taking multivitamins, and 20% reported taking vitamin C before races [169], although consumption rates as high as ~ 70% have been reported in small cohorts [170].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [169] Knechtle B, 2008, Asia Pac J Clin Nutr

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    L-glutamine is the most abundant amino acid in the body and has an essential role in lymphocyte proliferation and cytokine production.

    “L-glutamine is the most abundant amino acid in the body, with an essential role in lymphocyte proliferation and cytokine production [175].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [175] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    NSAID use can cause serious adverse effects on cardiovascular, musculoskeletal, gastrointestinal, and renal systems, which might be exacerbated by ultra-marathon running.

    “Notwithstanding, NSAID use can cause serious adverse effects on cardiovascular, musculoskeletal, gastrointestinal, and renal systems, all of which might be exacerbated by ultra-marathon running (for review, see [179]).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [179] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Up to 15% of legal supplements are inadvertently or deliberately contaminated with illegal drugs, which remain in the system for several hours following consumption and would result in a positive test for banned substances.

    “Finally, there is evidence that up to 15% of legal supplements are inadvertently or deliberately contaminated with illegal drugs, which remain in the system for several hours following consumption, and that would result in a positive test for banned substances [196, 197].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [196] source

      Not checked in the free run.

    • cites [197] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    There is an increased risk of GI-injury with NSAID use, which may be exacerbated in long-distance runners who already exhibit a greater incidence of GI-bleeding.

    “There is an increased risk of GI-injury with NSAID use, and this may be exacerbated in long-distance runners (contesting marathon and ultra-marathon) who already exhibit a greater incidence of GI-bleeding [189–191].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [189] source

      Not checked in the free run.

    • cites [190] source

      Not checked in the free run.

    • cites [191] source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Concern has been expressed about a possible causative role of NSAIDs on exercise-induced hyponatremia.

    “Frequent prophylactic use of NSAIDs is also associated with increased risk of renal side-effects [192, 193], and concern has been expressed about a possible causative role of NSAIDs on exercise-induced hyponatremia [194].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [194] source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The prevalence of NSAID use among ultra-marathon runners is as high as 60%, with 70% of runners using NSAIDs during racing.

    “The prevalence of NSAID use among ultra-marathon runners is as high as 60%, with 70% of runners using NSAIDs during racing [180, 181].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [180] source

      Not checked in the free run.

    • cites [181] Scheer BV, Burgos EV: The hidden danger of endurance races: analgesic use among ultramarathon runners. Abstracts from the 3rd European College of Sports and Exercise Physicians (ECOSEP) conference on 25–27 April 2013, 47(10). source

      Not checked in the free run.

84 of 84

  • The paper relies on this without support.

    Ultra-marathon runners are often reluctant to compromise their race preparation and/or recovery to volunteer for data-collection, particularly when invasive, time-consuming testing protocols are used.

    “Moreover, runners are often reluctant to compromise their race preparation and/or recovery to volunteer for data-collection, particularly when invasive, time-consuming testing protocols are used.”

  • The paper relies on this without support.

    Ultra-marathons are often contested in remote locations and environmental extremes which do not lend themselves to complex or invasive data-collection protocols.

    “Secondly, ultra-marathons are often contested in remote locations and environmental extremes which do not lend themselves to complex or invasive data-collection protocols, especially when requiring equipment that is difficult to transport.”

  • The paper relies on this without support.

    Training on challenging, variable, and uneven terrain, and in extremes of temperature and/or altitude, will notably increase the caloric and CHO requirements.

    “Training on challenging, variable, and uneven terrain, and in extremes of temperature and/or altitude, will notably increase the caloric and CHO requirements.”

  • The paper relies on this without support.

    The train-low strategy has been scarcely studied in relation to ultra-marathon training.

    “The above-mentioned strategy has been scarcely studied in relation to ultra-marathon training and should, therefore, be practiced tentatively.”

  • The paper relies on this without support.

    Keto-adaptation may take several weeks or months.

    “While debate exists, keto-adaptation may take several weeks or months, indicating that sustained tolerance to high-fat intake may be necessary in order that the individual acquire the full benefits.”

  • The paper relies on this without support.

    Ketogenic diets are associated with acute negative symptoms, including fatigue, headaches, poor concentration, lethargy, GI discomfort, nausea, and weight loss.

    “Notwithstanding the available research which indicates a degree of benefit, ketogenic diets have been associated with acute negative symptoms, including: fatigue, headaches, poor concentration, lethargy, GI discomfort, nausea, and weight loss.”

  • The paper relies on this without support.

    As training volume and/or intensity increase, relatively greater amounts of dietary CHO are required to fuel performance and minimize the risk of injury.

    “As training volume and/or intensity increase (e.g., an increase in running mileage or a transition to interval training), relatively greater amounts of dietary CHO will be required to fuel performance and minimize the risk of injury.”

  • The paper relies on this without support.

    Satisfying metabolic demand for protein is a prerequisite for both recovery and general health.

    “Satisfying metabolic demand for protein is, therefore, a prerequisite for both recovery and general health.”

  • The paper relies on this without support.

    The substantial training distances of ultra-marathon are associated with high levels of mechanical stress.

    “The substantial training distances of ultra-marathon are associated with high levels of mechanical stress.”

  • The paper relies on this without support.

    No existing studies have evaluated the efficacy of L-leucine specifically for ultra-marathon runners.

    “Although there are no existing studies on the efficacy of L-leucine specifically for ultra-marathon runners”

  • The paper relies on this without support.

    The absolute carbohydrate requirements for ultra-marathon racing are unclear.

    “Nevertheless, the absolute CHO requirements for ultra-marathon racing are unclear.”

  • The paper relies on this without support.

    Anecdotal evidence indicates that effervescent electrolyte tablets and liquid electrolytes added to water can compromise drink palatability, particularly during long races or those contested in the heat, thereby resulting in reduced fluid consumption.

    “Indeed, there is anecdotal evidence that effervescent (dissolvable) electrolyte tablets, and liquid electrolytes added to water, can compromise drink palatability, particularly during long races or those contested in the heat, thereby resulting in reduced fluid consumption.”

  • The paper relies on this without support.

    It is unlikely that the recommended rate of sodium intake will be achieved from foods alone.

    “although it should be noted that it is unlikely that the recommended rate of sodium intake will be achieved from foods alone.”

  • The paper relies on this without support.

    The concentrations of some electrolytes (e.g., sodium) in many commercially-available electrolyte replacement products are insufficient to meet the recommended intakes.

    “In addition, the concentrations of some electrolytes (e.g., sodium) in many commercially-available electrolyte replacement products are insufficient to meet the recommended intakes.”

  • The paper relies on this without support.

    It is possible to consume adequate amounts of both fluid and sodium during prolonged exercise, with sufficient practice.

    “Such poor practice must be challenged, since it is possible to consume adequate amounts of both fluid and sodium during prolonged exercise, with sufficient practice.”

  • The paper relies on this without support.

    Nutritional strategies practiced in training well in advance of racing allow sufficient time for GI adaptations that optimize CHO absorption and mitigate GI distress.

    “Nutritional strategies should be practiced in training, well in advance of racing, to allow sufficient time for GI adaptations that optimize CHO absorption, and mitigate GI distress.”

  • The paper relies on this without support.

    Eating regardless of nausea can give the most relief from symptoms when nausea is caused by hypoglycemia.

    “Although counterintuitive, there may be some instances when eating regardless of nausea will give the most relief from such symptoms, especially when nausea is caused by hypoglycemia.”

  • The paper relies on this without support.

    Caffeine overconsumption has ergolytic and/or dangerous effects.

    “Finally, given the ergolytic and/or dangerous effects of caffeine overconsumption, athletes are advised to double-check their doses, ensure their intakes are congruent with the empirical data and safety guidelines, and give special consideration to the method of delivery (fluid vs. tablets vs. gum).”

  • The paper relies on this without support.

    The importance of afferent pain signals to indicate potential tissue damage cannot be underestimated.

    “the importance of afferent pain signals to indicate potential tissue damage cannot be underestimated.”
19 of 19

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • During training and competition, fiber intake may be reduced to avoid potential GI issues including gas and distension.

    “During training and competition, fiber intake may be reduced to avoid potential GI issues including gas and distension [141].”

    From The athletic gut microbiota (2020) · cites this paper as [141]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Food marked sodium-rich despite not exceeding the stated threshold

    Minor

    The oat bar is listed with 250 mg sodium and marked as sodium-rich, but the table defines that mark as indicating more than 250 mg.

  • Stated calorie-per-kilogram range excludes table estimates

    Minor

    The evidence statement gives a lower bound of approximately 38 Kcal·kg− 1·d− 1, but Table 3 lists estimates of 34.8 and 34.9 Kcal·kg− 1·d− 1 for runners in the population being described.

2 of 2

Cites

Flagged first, then by citations

3 of the 210 references couldn’t be matched to a known paper.

Research works printed but not linked: 12

  1. Sawka MN, 1999, Exerc Sport Sci Rev, 27, 167
  2. Blennerhassett C, 2018, Int J Sport Nutr Exerc Metab, 17, 1
  3. Bilsborough SA, 2003, Asia Pac J Clin Nutr, 12, 396
  4. Son HJ, 2015, Biol Sport, 32, 357
  5. Negro M, 2008, J Sports Med Phys Fitness, 48, 347
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Authors
Tiller, N. B., Roberts, J. D., Beasley, L., Chapman, S., Pinto, J. M., Smith, L., Wiffin, M., Russell, M., Sparks, S. A., Duckworth, L., O’Hara, J., Sutton, L., Antonio, J., Willoughby, D. S., Tarpey, M. D., Smith-Ryan, A. E., Ormsbee, M. J., Astorino, T. A., Kreider, R. B., McGinnis, G. R., Stout, J. R., Smith, J. W., Arent, S. M., Campbell, B. I., & Bannock, L.
Affiliations
  • The Lundquist Institute (US)
  • Anglia Ruskin University (GB)
  • Leeds Trinity University (GB)
  • Edge Hill University (GB)
  • Leeds Beckett University (GB)
  • Carnegie School of SportLeeds Beckett University Leeds UK
  • College of Health Care SciencesNova Southeastern University Fort Lauderdale FL USA
  • Baylor University (US)
  • East Carolina University (US)
  • Department of Exercise and Sport ScienceUniversity of North Carolina Chapel Hill NC USA
  • Florida State University (US)
  • California State University, San Marcos (US)
  • Texas A&M University (US)
  • University of Nevada, Las Vegas (US)
  • University of Central Florida (US)
  • Mississippi State University (US)
  • University of South Carolina (US)
  • University of South Florida (US)
  • Institute of Performance Nutrition London UK
Corresponding author
  • Tiller, Nicholas B.
  • Roberts, Justin D.
ORCID
Venue
Journal of the International Society of Sports Nutrition
Publisher
Informa UK Limited
Published
2019-01-15
Volume
16
Issue
1
Pages
50-50
ISSN
1550-2783 (ISSN-L)
DOI
10.1186/s12970-019-0312-9
PMC
PMC6839090
OpenAlex
W2981258550
Semantic Scholar
ae1113d60790ac0a9f3d6c927ef6d97a7669a06f
Cited by
164
References
210
Citations by year
2026: 17 · 2025: 28 · 2024: 27 · 2023: 20 · 2022: 29 · 2021: 22 · 2020: 19 · 2019: 1 · 2017: 1
FWCI
2.05
Type
journal article
Language
en
Open access
Licence
Locations
  • Journal of the International Society of Sports Nutrition (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Edge Hill University Research Information Repository (Edge Hill University) (publishedVersion, cc-by)
  • Leeds Beckett Repository (Leeds Beckett University) (acceptedVersion)
  • Anglia Ruskin Research Online (Anglia Ruskin University) (acceptedVersion)
  • SHURA (Sheffield Hallam University Research Archive) (Sheffield Hallam University) (acceptedVersion)
  • Digital Scholarship - UNLV (University of Nevada Reno) (submittedVersion, cc-by)
  • Scholar Commons (University of South Carolina) (submittedVersion, cc-by)
  • The Scholarship East Carolina University's Institutional Repository (East Carolina University) (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Figshare (submittedVersion, cc-by-nc-nd)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
Keywords
ultramarathon, carbohydrate intake, mitochondrial function, protein intake, caloric deficit, hyponatremia, low FODMAP diet, gastrointestinal distress, ketogenic diet, ketone esters, training periodization, lean body mass
MeSH terms
Energy Intake, Competitive Behavior, Dietary Carbohydrates, Dietary Proteins, Humans, Nutritional Requirements, Physical Endurance, Running, Societies, Athletic Performance, Athletes, Sports Nutritional Physiological Phenomena

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

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