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Acute Ingestion of a Ketone Monoester without Co-ingestion of Carbohydrate Improves Running Economy in Male Endurance Runners.

PMID 37565450 (2024): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

Last updated/Feb 23, 2026, 10:34 PM

Study note • PMID 37565450

Acute Ingestion of a Ketone Monoester without Co-ingestion of Carbohydrate Improves Running Economy in Male Endurance Runners.

Medicine and science in sports and exercise2024 • DOI 10.1249/MSS.0000000000003278
Evidence C67/100
Action 2: Consider

Worth trying if it fits your goal and context.

ELI5

In plain language

Acute ingestion of a ketone monoester, with and without co-ingestion of carbohydrate, was investigated for effects on running economy (RE), time to exhaustion (TTE), and other related indices of… (randomized trial; runners).

The abstract doesn’t indicate a clear change in Time to exhaustion, Time-trial performance under the tested conditions. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: Acute ingestion of a ketone monoester, with and without co-ingestion of carbohydrate, was investigated for effects on running economy (RE), time to exhaustion (TTE), and other related indices of…
  • The abstract doesn’t indicate a clear change in Time to exhaustion, Time-trial performance under the tested conditions.
  • Population: runners.
  • Protocol cues (title/abstract): 750 mg • 8 min • 14 km.

Protocol

Protocol (as reported)

  • Intervention/exposure: carbohydrate, carb (vs placebo).
  • Dose/time/duration cues in abstract/title: 750 mg • 8 min • 14 km.
  • Outcomes: Time to exhaustion, Time-trial performance, Fat oxidation.
  • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.

Fit

Who it helps, and who should skip it

Who it helps

  • Athletes similar to the study population (runners) working on fueling.
  • Athletes who can measure Time to exhaustion, Time-trial performance, Fat oxidation with a repeatable workout or time-trial effort.

Who should skip

  • If you have symptoms or conditions that make the intervention risky, get professional guidance.
  • If you’re near race day and can’t safely test, defer the experiment.

Methods

What the study actually did

  • Design: randomized trial (placebo-controlled).
  • Population: runners.
  • Comparator: placebo.
  • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
  • Protocol cues mentioned: 750 mg • 8 min • 14 km.
  • Source: PubMed PMID 37565450 (2024) — Medicine and science in sports and exercise.

Results excerpt

What the abstract reports

RE was lower at each submaximal running speed (effect size = 0.48-0.98) by an average of 4.1% in KE compared with CHO, but not between CHO + KE and CHO.

Note: excerpts are short; for full context, read the paper.

Limits

Limitations & bias

  • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
  • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
  • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
  • This is performance information, not medical advice.

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Sources