Do you have to eat a high-carbohydrate diet to perform in endurance sport?

Neither side addresses a general reader, and the elite-versus-recreational split is the hidden axis of the whole dispute. Her evidence is in world-class race walkers and Olympic medallists, and she reports the decrement being larger in the highest-calibre athletes; his is in recreational and trained athletes. He argues her findings do not generalise down; she argues his do not generalise up.

Both bodies of evidence are overwhelmingly male: her Supernova trial is 13 men. Neither side engages the female-specific hormonal argument Stacy Sims makes at sim-carbs-endurance, and Burke has separately published audits counting exactly this under-representation. None of this is settled for women, and none of it is advice for someone who is not training for a race.

Documented in a paper they both wrote and both approved. From Table 1, Points of agreement: carbohydrate ingestion during prolonged exercise improves performance by maintaining euglycemia, including in keto-adapted athletes; adaptation to an LCHF diet substantially increases fat oxidation; that adaptation can occur in as few as 5 to 7 days in elite athletes; high rates of fat oxidation occur at 65 percent VO2max and above in adapted athletes; the adaptation raises the oxygen requirement for the same power output; and respiratory gas analysis is not reliable above the lactate threshold.

What is left, in their own words: 'whether strategies to promote highest rates of CHO oxidation provide advantages over the amounts needed to prevent hypoglycemia'.

Their own answer, in Table 3 of the consensus paper, eight items agreed by both: stable-isotope measurement of fat oxidation above 80 percent VO2max; the time course of adaptation over months rather than weeks; the consequences of the increased oxygen cost; randomised comparisons in real-world competition, in endurance and team sports; an elite versus regular athlete comparison; the effect of combining several dietary strategies rather than testing one; a dose response for carbohydrate during prolonged exercise, to test whether preventing hypoglycaemia is really its only role; and blinding both athletes and researchers to manage the belief effect.

Note the disclosure asymmetry a replication would also settle: his stake is in books and a shareholding pointing one way, hers is in advisory roles and travel grants she discloses as pointing both ways.