REF-1423 · Aussieker et al., 2026 · International Journal of Sport Nutrition and Exercise Metabolism, Ahead of Print, pages 1-10 · Paper · PubMed
Do elite sports-nutrition rules fit a recreational athlete?
Partly, in ten experts' 3-minute opinions (C): a slower marathoner needs fewer grams per hour (a model), 1.6 g/kg protein is a target, not a gate; train-low is not advised.
Main caveat: Design. Ten 3-minute opinions with three slides each, written up with limited word counts and references.
The Professionals in Nutrition for Exercise and Sport (PINES) run a "rapid-fire" session at the American College of Sports Medicine Annual Meeting in which ten researchers or practitioners each get three slides and 3 min to judge a provocative "myth".
The 2026 session asked whether sports-nutrition guidance written around elite sport fits recreational athletes, and this paper is its written summary. The verdicts: guidelines are not built mainly on elite athletes (in one audit only about 4% of supplement studies were on Tier 4-5 athletes), and whether they are too serious for recreational athletes is equivocal (Burke).
A recreational marathoner does not need elite grams per hour: in a presenter's model, a 2-h marathoner at 94% of VO2max needs about 90 g/h of exogenous carbohydrate and a 4-h marathoner at 60% about 53 g/h, but over the race both need a similar total, about 180 g and 212 g (Stellingwerff). 1.6 g/kg/day of protein is a useful "fail-safe" target, not a threshold below which training stops working (Zupančič).
Nitrate does not help all athletes equally: trained endurance athletes may gain less, and the oral bacteria that turn nitrate into nitrite differ between people (Vanhatalo).
A structured drinking plan is not needed by most recreational athletes, who likely stay within 0-4% body-mass loss, but about one in five finishers in one marathon over-drank or lost more than 4%, and for them, or for anyone wanting a tighter range, a plan from measured sweat loss may help (Wardenaar).
Bicarbonate loading is plausible below elite level, with mixed performance results, a large dose for a heavy athlete and an emerging, unconfirmed kidney-marker benefit in the heat (Siegler). Exercise may raise micronutrient needs, but a varied diet usually covers them; supplement after a status assessment (Manore).
Eating after 8 pm is not bad for athletes who train in the evening: the recovery meal comes first, and most of the research on late-eating harms is in non-athletes (Haudum). Recreational athletes are not at greater vitamin D risk because of their level; sun exposure, season, latitude, skin, clothing and body fat decide it (Larson-Meyer).
Train-low is not advised for recreational athletes: it raised muscle signalling in competitive athletes but cut their training intensity and did not clearly improve performance (Hawley).
Our reading: the session agrees with the base on most lines (no universal drinking plan, and a weigh-in to show who needs one, SYNTH-68, though the session never mentions thirst; supplements after status and only for a matching event, SYNTH-67; protein near 1.6-1.8 g/kg/day, SYNTH-69; train-low as no performance tool, REF-218, REF-543).
It goes further than the base on train-low for recreational athletes and on routine winter vitamin D, and its marathon table gives a lower hourly rate than the base's house target on inputs that understate the 4-h runner's energy cost by about a third (our arithmetic).
Protocol
Format: written summary of a live session; n = 10 presenters and no participants. Each presenter stated a proposition, gave the evidence they chose, a verdict ("confirmed", "busted" or "plausible/equivocal"), an explanation and one or two "Additional reading" references; the paper ends with conclusions grouped in four themes and a nontechnical summary. No search strategy, inclusion criteria or grading of evidence.
Presenters and questions: (a) Burke — are guidelines built on elite studies and too serious for recreational athletes? (b) Stellingwerff — in-race carbohydrate for recreational vs elite marathoners; (c) Zupančič — must recreational athletes eat 1.6 g/kg/day of protein?(d) Vanhatalo — nitrate in elite vs recreational athletes; (e) Wardenaar — do recreational athletes need a structured fluid plan? (f) Siegler — is bicarbonate loading relevant only to elites? (g) Manore — micronutrients above the RDA; (h) Haudum — eating after 8 pm; (i) Larson-Meyer — vitamin D and indoor jobs; (j) Hawley — training with low carbohydrate availability.
The marathon table (Table 1) is a model, "mainly based, but not solely" on Jones 2021 (REF-822), Lukasiewicz 2024 and O'Brien 1993; how the exogenous column was derived from the energy columns is not stated.
Self-citation: several answers rest on the presenters' own or co-authors' papers: Siegler's kidney-marker study (Masoud 2025), Hawley's whole train-low answer (his reviews Hawley & Burke 2010 and Hawley 2018, the Yeo 2008 trial he and Burke co-authored, REF-1096, and the Burke, Whitfield & Hawley 2025 commentary, which Burke also gives as additional reading), Vanhatalo's nitrate and oral-microbiome studies (Kadach 2023, Vanhatalo 2025), Larson-Meyer's status-assessment review (Larson-Meyer 2018), Manore's B-vitamin review (Woolf & Manore 2006), and the McKay classification and supplement audit co-authored by Stellingwerff and Burke.
Funding and interests (as printed): no funding statement for the article. Burke has been an unpaid member of many expert panels and working groups that wrote sports-nutrition guidelines. Stellingwerff consults with Science in Sport (a sports-nutrition company) and periodically receives an honorarium; he presented the in-race carbohydrate question.Wardenaar received grants unrelated to the session (National Science Foundation, Arizona Board of Regents, Arizona Parks & Trails, Pac-12 Health and Well-Being Initiative, the Collegiate and Professional Sports Dietitians Association, Standard Process Inc., Kraft Heinz Company, Unilever Corporation, FrieslandCampina) and has been an unpaid scientific advisor of the FuelWarden app since the fall of 2025; he presented the fluid question.All other authors report no further conflicts. All authors are PINES members, and PINES hosted the session.
Key Results
| Question | Verdict (as printed) | What the answer rests on | Kind of evidence |
|---|---|---|---|
| (a) Guidelines come from elite studies; too serious for recreational athletes | Busted that they address elites; equivocal whether too serious | Of 1,867 studies of six evidence-based supplements, 81 (about 4%) were on Tier 4-5 athletes, 1,272 participants (Smith 2022 audit, not in the base) | One measured audit, then opinion |
| (b) Recreational marathoners need elite in-race carbohydrate | Busted for grams per hour; confirmed for total grams; both busted if the intake causes GI trouble | Table 1 below | Model |
| (c) Recreational athletes must eat 1.6 g/kg/day of protein | Busted: a useful target and a "fail-safe", not a mandatory threshold | Morton 2018's breakpoint of 1.62 g/kg/day for fat-free-mass gains (REF-579, A; resistance training) | Opinion on one meta-analysis |
| (d) Nitrate helps elite and recreational athletes equally | Busted | Trained endurance athletes (VO2max above 60 mL/kg/min) may not gain (Shannon 2022, an expert consensus), even on a dose that helped moderately and low-fit people (Porcelli 2015, one trial); oral-microbiome studies (Vanhatalo 2025, on ageing) | A consensus, one trial and mechanism |
| (e) Recreational athletes need a structured fluid plan | Busted as stated; plausible for some | About 20% of 643 marathon finishers over-drank or lost more than 4% of body mass (Zouhal 2011, one race, 9-16 °C); Goulet 2013 argued that in real-world conditions impairment may not appear consistently before about 4%; sweat rates commonly 0.8-1.6 L/h as the session quotes Barnes 2019 (REF-221, whose base entry gives endurance athletes 1.28 ± 0.57 L/h); poor self-estimation of sweat loss (O'Neal 2020) | One field study and reviews |
| (f) Bicarbonate loading is only for elites | Busted that lactate is the enemy; plausible that recreational athletes could load | About 0.3 g/kg; reviews put the gain near 2-3%; newer delivery forms cut GI stress (Gough & Sparks 2024, at rest in well-trained male cyclists); smaller rises in kidney-injury markers during work in the heat (Masoud 2025, co-authored by the presenter) | Reviews and single studies |
| (g) Athletes need micronutrients above the RDA | "No, the myth is plausible": extra need is usually met by eating more; supplement only after a status assessment | Larson-Meyer 2018; Beck 2021 | Opinion on reviews |
| (h) Eating after 8 pm harms performance or recovery | Busted as stated | No evidence that a fixed 8 pm cut-off helps athletes; time-restricted-eating benefits are reported in non-athlete and at-risk groups (Parr 2019); recovery needs energy and carbohydrate (Burke 2006; Thomas 2016, REF-063); sleep-promoting foods preliminary (Rackard 2025) | Absence of evidence, then opinion |
| (i) Recreational athletes have more vitamin D risk because of indoor jobs | "No, the myth is plausible": risk depends on individual and lifestyle factors, not level | Prevalence varies by sport, environment, skin colour, age and genetics (Hacker 2025; Larson-Meyer 2015); dosing statements without a trial behind them in the text | Opinion |
| (j) Recreational athletes should train low | Busted | In competitive athletes training more than 10 h a week, 3-10-week train-low programmes raised selected genes, proteins and mitochondrial biogenesis (Hawley & Burke 2010; Hawley 2018, reviews), but in Yeo 2008 (REF-1096) self-selected training intensity fell 7-8% with no clear performance benefit | Reviews, one trial and reasoning |
The marathon model (Table 1; a presenter's model, not a measurement):
| VO2max (mL/kg/min) | Body mass (kg) | % VO2max at marathon pace | RER | kcal/min | kcal for the marathon | % carbohydrate (from RER) | Carbohydrate kcal | Exogenous carbohydrate, g/h | Exogenous carbohydrate, total g | |
|---|---|---|---|---|---|---|---|---|---|---|
| 2-h marathoner | 70.0 | 58.0 | 94.0% | 0.99 | 19.8 | 2,375 | 84.0% | 1995 | 90 | 180 |
| 4-h marathoner | 40.0 | 75.0 | 60.0% | 0.85 | 8.8 | 2,100 | 50.4% | 1059 | 53 | 212 |
The presenter's reading: an elite runs at a far higher absolute and relative intensity and almost entirely on carbohydrate, so the hourly need is about double; the recreational runner takes twice as long, so the total is about the same and there is more time to take it in. A separate cited model gave 90 ± 23 g/h for men and 108 ± 22 g/h for women at 2-h marathon pace (Lukasiewicz 2024).
A number that does not add up (our arithmetic): 60% of a VO2max of 40.0 is 24 mL/kg/min; at 4-h marathon pace (42.195 km in 240 min) that is an oxygen cost of about 137 mL/kg/km.The base's measured costs are 191 ± 19 mL/kg/km in world-class men at 2-h pace (REF-822) and 212-215 mL/kg/km at minute 15 of a 90-min run at 13.1 km/h, 218-226 by minute 90, in well-trained men (REF-1144). At about 200 mL/kg/km a 4-h marathon needs about 35 mL/kg/min, about 88% of a VO2max of 40, and the runner as specified would take about 5.9 h.Put as energy, 2,100 kcal for a 75-kg runner over 42.195 km is about 0.66 kcal/kg/km, against about 0.97 kcal/kg/km for the 58-kg elite in the same table.Inference: the table's own 8.8 kcal/min matches 60% of a VO2max of 40 at 75 kg (1.8 L/min of oxygen, about 8.75 kcal/min at an RER of 0.85), so the fault is in pairing that intensity with a 4-h finish, and the race's energy cost is understated by roughly a third whichever input is wrong.How the exogenous column follows is not stated (at 4 kcal/g it is about 36% of the carbohydrate burned for the elite and 80% for the 4-h runner), so the error in 53 g/h and 212 g cannot be computed: for a runner who really finishes in 4 h both are more likely low than high, and "about half the hourly need" probably overstates the gap; a runner who really holds 60% of a VO2max of 40 takes about 5.9 h, where the hourly figure could stand but the total would be about half as large again.
A second inconsistency (our arithmetic): an RER of 0.99 corresponds to about 97% carbohydrate oxidation by linear interpolation between 0.71 (fat) and 1.00 (carbohydrate), and the text itself says "nearly 100%", but the table uses 84.0%; at 0.85 the same arithmetic gives about 48%, close to the table's 50.4%, and 84% corresponds to an RER near 0.95. The exogenous column is not derived from these figures in any stated way.
Text against table: the text calls the elite's energy cost "twofold" the recreational runner's (19.8 vs 8.8 kcal/min, 2.25 times) and the recreational hourly need "about half" (53 vs 90 g/h, 59%) (our arithmetic).
What is measured, what is not: the audit numbers in (a) and the field numbers in (e) are measured data from one cited study each; the marathon figures in (b) are a model; the protein, nitrate, bicarbonate, micronutrient, late-eating, vitamin D and train-low verdicts are the presenters' reading of the papers they chose.
Mechanisms
Authors' interpretation (carbohydrate): carbohydrate need per hour follows absolute intensity and carbohydrate dependence, which depend on training status, body mass, sex, fibre type and economy; an elite near 94% of VO2max runs almost entirely on carbohydrate, which needs 6-8% less oxygen per unit of ATP than fat, while a slower runner burns less per minute for longer.
Authors' interpretation (protein): the training stimulus is the main driver of muscle mass and strength, and protein permits and optimises the response; endurance exercise raises amino-acid oxidation, and habitual high-protein diets raise the capacity to oxidise amino acids, so the requirement moves with modality, energy availability and habitual intake.
Authors' interpretation (nitrate): oral bacteria reduce nitrate to nitrite, the precursor of nitric oxide; denitrification-type bacteria yield nitrite, while bacteria that reduce nitrate to ammonia remove nitric-oxide precursors, so a mouth dominated by the latter blunts the plasma nitrite rise. Chronic nitrate intake shifts the oral microbiome toward nitrite producers.The presenter adds that the smaller response of highly trained athletes does not establish a systematic athlete-nonathlete difference in nitrate-reducing capacity.
Authors' interpretation (bicarbonate): lactate is a fuel, a gluconeogenic precursor and a signal, not the enemy; the rise in intracellular hydrogen ions, with inorganic phosphate, is thought to impair cross-bridge function, and bicarbonate loading raises blood buffering against it.
Authors' interpretation (train-low): upregulating muscle proteins of oxidative metabolism is not rate-limiting for endurance performance in trained athletes, and "peripheral" muscle adaptations are unlikely to set the ceiling for people training under 10 h a week, so lower training intensity and higher effort are a poor trade.
Authors' interpretation (vitamin D): skin synthesis from UVB is the main source; darker skin, sun avoidance, excess body fat, covering clothing and sunscreen reduce status, and fortified foods alone will not hold sufficient status without UVB.
Inference: for every verdict, the strength of the evidence is that of the studies named in the Key Results, not of the session; most of them are not in the base.
Practical Application
Do elite sports-nutrition rules fit a recreational athlete? Partly, in ten experts' 3-minute opinions (C): a slower marathoner needs fewer grams per hour (a model), 1.6 g/kg protein is a target, not a gate; train-low is not advised.
Marathon fuel, per hour and in total: the point that survives the model's flaws is that a slower runner burns carbohydrate more slowly but for longer, so the race total can match an elite's.The 53 g/h for a 4-h runner is a model with an implausibly low energy cost (our arithmetic) and does not replace the base's house range; marathoners in one field survey averaged 35 g/h (REF-787, B+). The race-fuel decision is in SYNTH-64 and SYNTH-02; rehearse it in training, as the presenter also says.
Protein: an endurance athlete keeps the base's ~1.8 g/kg/day default, set from measured requirements (REF-725, B+; REF-151, A); this session adds that falling short on some days does not stop training from working, since in Morton's meta-analysis the gains in fat-free mass levelled off near 1.6 g/kg/day (REF-579, A, resistance training) and the training stimulus remains the main driver (SYNTH-69).
Drinking: drink to thirst (SYNTH-68, on REF-776, A-); weighing before and after a few long sessions tells a recreational athlete whether they belong to the minority who gain weight or lose more than about 4%, for whom a plan built on measured sweat loss may help (in the base, capped at that loss). The one-in-five figure is one race in mild weather.
Eating late after evening training: eat the recovery meal; there is no evidence that a fixed 8 pm cut-off helps athletes, and skipping dinner after an evening session can cost recovery and the day's energy and nutrients (opinion, C; SYNTH-69).
Train-low: for a recreational athlete on under ~10 h a week the presenter's advice is to train longer or faster with normal fuelling instead; the base keeps train-low as an option on easy sessions with no promise of a faster race (SYNTH-51, REF-218 A-, REF-543 B+), and this opinion does not address the positive sleep-low trial in trained triathletes (REF-003, B+).
Supplements: level is not the test, the event and the person are (SYNTH-67): nitrate may help a highly trained athlete less (a consensus and one trial cited; the base calls this contested: its umbrella review points the same way, REF-3493, A, while McMahon's meta-analysis found no moderation by fitness, REF-353, A); bicarbonate follows the stand's event window (REF-354, A), and its dose by body mass is large for a heavy athlete (about 25.5-27.0 g at 85-90 kg); micronutrients are supplemented after a status check, with food first (REF-358, A); for vitamin D the presenter would add at least the 600 IU RDA through winter above ~33° latitude, which the base does not adopt (REF-355, B+: no screening or high doses without a clinical reason).
Limitations
Design. Ten 3-minute opinions with three slides each, written up with limited word counts and references; no search, no inclusion criteria, no grading, one presenter per question and no dissent recorded. The authors say so themselves. Verdict labels are coarse and sometimes hard to read: "No, the myth is plausible" for micronutrients and for vitamin D means that the statement is partly true, not that it is confirmed.
The marathon model. Unvalidated, with no participants; its 4-h runner spends about a third less energy per kilometre than measured running costs imply, and its carbohydrate share at an RER of 0.99 does not match the RER (our arithmetic, Key Results). Its hourly and total figures should not be quoted as measured needs.
Single studies carry several verdicts. The one-in-five drinking figure is one French marathon in 2009 at 9-16 °C (Zouhal 2011); the trained-athlete nitrate claim rests on an expert consensus and mainly one trial (Shannon 2022; Porcelli 2015); the kidney-marker benefit of bicarbonate is one study of markers, co-authored by the presenter (Masoud 2025); the train-low verdict leans on one trial with 7 cyclists per group (Yeo 2008, REF-1096, B).Most cited studies are not in the base.
Not weighed against the base's evidence. The train-low answer does not mention the positive sleep-low trial (REF-003, B+); the fluid answer's 0-4% band rests on an argument that impairment appears near 4% in the field (Goulet 2013, not in the base; the earlier meta-analysis is REF-1365, B+), while the base keeps a ~2% line for the heat (SYNTH-68).
Internal tension. The micronutrient answer asks for a status assessment before any supplement; the vitamin D answer recommends at least the 600 IU a day RDA through winter above ~33° latitude even with adequate summer stores, and says that athletes with limited sun may need at least 1,500-2,000 IU a day, doses not tested in the text.Its sunlight advice (5-30 min to arms, legs and back near solar noon without sunscreen, citing a 2013 review) is not weighed against skin-cancer risk; the base does not carry it as advice.
Reporting. The vitamin D cut-offs are printed as "< 50 nmol/L and < 75 ng/ml"; 75 ng/mL would be about 187 nmol/L, so the second unit is presumably a misprint for 75 nmol/L (inference). The text's "twofold" energy cost and "about half" hourly need do not match its own table exactly (Key Results).
Interests. Stellingwerff, who presented the carbohydrate question, consults for a sports-nutrition company; Wardenaar, who presented the fluid question, advises the FuelWarden app unpaid; Burke sits on guideline panels unpaid; several answers cite the presenters' own work. No funding statement. Ahead of print: volume and issue not yet assigned.
How this entry was checked and changed
Why this level
expert opinion by the rubric. The authors write that the answers reflect the individual presenters' perspectives and are not comprehensive reviews of the literature; each answer rests on a few cited papers, several by the presenters themselves, and the marathon carbohydrate table is an unvalidated model. The presenters lead the field, but the rubric's B+ for an authoritative narrative review does not fit a 3-minute opinion without a search; a study it cites keeps its own level where the base holds it
Full text (checked 2026-10-29)
Among 1,867 investigations of evidence-based performance supplements, only 81 (∼4%) were undertaken on Tier 4–5 athletes, 1,272 participants in total (full text)
Table 1 model: 2-hr marathoner 70.0 ml·kg−1·min−1, 58.0 kg, 94.0% of VO2 at marathon pace, RER 0.99, 19.8 kcal/min, 2,375 kcal, 84.0% CHO oxidation, 90 g/hr and 180 g exogenous CHO; 4-hr marathoner 40.0, 75.0 kg, 60.0%, RER 0.85, 8.8 kcal/min, 2,100 kcal, 50.4%, 53 g/hr and 212 g (full text)
A cited model gave 90 ± 23 g/hr in males and 108 ± 22 g/hr in females for a 2-hr marathon (Lukasiewicz et al., 2024) (full text)
Morton 2018's breakpoint was 1.62 g·kg−1·day−1; 1.6 g·kg−1·day−1 is called a practical "fail-safe" recommendation rather than a universal requirement (full text)
Trained endurance athletes (VO2max > 60 ml·kg−1·min−1) may not gain ergogenic benefits from nitrate supplementation (full text)
Approximately 20% of 643 marathon finishers (France, May 2009; 9 °C–16 °C) over-consumed fluids or lost more than 4% BM; most athletes likely stay within 0%–4% BM loss; sweat rates commonly range from 0.8 to 1.6 L/hr (full text)
About 0.3 g/kg BW of sodium bicarbonate is 25.5–27.0 g for someone weighing 85–90 kg; reviews and consensus statements put the potential performance improvement at ∼2%–3% (full text)
No evidence shows that a fixed 8:00 p.m. cut-off improves athletes' recovery or performance (full text)
With limited sun exposure at least 1,500–2,000 IU/day vitamin D; above or below ∼33° latitude at least the US RDA of 600 IU during winter (full text)
In competitive endurance athletes undertaking >10 hr of workouts per week, 3–10-week train-low programmes went with 7%–8% lower self-selected training intensities and no clear benefit to endurance performance (Yeo et al., 2008) (full text)
Stellingwerff consults with Science in Sport and periodically receives an honorarium; Wardenaar has been an unpaid scientific advisor of the FuelWarden app since the fall of 2025 (full text)