Ketone ester supplementation did not improve performance, cognitive function, or sleep during an 8-day simulated cycling race
In a double-blind, placebo-controlled trial, 18 well-trained cyclists completed an 8-day simulated cycling stage race. Ketone monoester supplementation (25g twice daily) did not improve exercise performance, sleep, or cognitive function compared to placebo. The race induced fatigue (peak heart rate drop ~11 bpm, time trial performance drop ~3%), but no clear benefit of KE was observed.
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
Ketone ester supplementation did not improve performance, cognitive function, or sleep during an 8-day simulated cycling race The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 42/100 (low).
The Claim
Ketone ester supplementation did not improve performance, cognitive function, or sleep during an 8-day simulated cycling race
This conclusion is most relevant to: Well-trained cyclists (n=18) participating in an 8-day simulated cycling stage race.
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Ketone Ester Intake Did Not Improve Performance, Neither Cognitive Function or Sleep, During an 8-Day Simulated Cycling Race. (Medicine and science in sports and exercise, 2026) —
How It Works
The proposed biological pathway:
- ▸Ketone esters increase blood ketone levels
- ▸Expected to enhance post-exercise recovery and reduce mental fatigue
- ▸Hypothesized to improve sleep and subsequent performance
- ▸Result: No significant improvement in performance, sleep, or cognitive function
Who Might Benefit
Evidence fit by population:
- ▸Well-trained cyclists (n=18) participating in an 8-day simulated cycling stage race
Recommended Dose
25g KE twice daily (post-stage and pre-sleep)
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Small sample size (n=18) with uneven group distribution (KE n=8, CON n=10)
- ▸Simulated race may not fully replicate real-world multi-day event conditions
- ▸No direct measurement of cognitive function reported in abstract (only mentioned in title/context)
Frequently Asked Questions
Did ketone ester supplementation improve cycling performance in this study?▼
No, ketone ester supplementation did not improve 30-minute time trial performance or other performance measures during the 8-day simulated race.
Did ketone esters affect sleep quality or quantity?▼
No, neither the KE supplementation nor the race had a significant impact on sleep, as measured daily during the study.
What was the dose and timing of ketone ester intake?▼
Participants received 25g of ketone monoester immediately after each stage and 30 minutes before sleep, totaling 50g per day.
Who were the participants in this study?▼
Eighteen well-trained cyclists, with 8 in the ketone ester group and 10 in the placebo group, completed the 8-day simulated cycling race.
References
- 1.Engelbrecht L, Lauriks W, Robberechts R, Stalmans M, Ramaekers M, Terblanche E, Koppo K, Poffé C. “Ketone Ester Intake Did Not Improve Performance, Neither Cognitive Function or Sleep, During an 8-Day Simulated Cycling Race..” Medicine and science in sports and exercise, 2026. PMID: 42658808 DOI: 10.1249/MSS.0000000000004119