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Study note

Carbohydrate ingestion during endurance exercise improves performance in adults.

PMID 21411610 (2011): carbohydrate, carb — Time to exhaustion, Time-trial performance, Fat oxidation (study note for endurance athletes).

Updated Jul 22, 2026

Read the study note

Study note • PMID 21411610

Carbohydrate ingestion during endurance exercise improves performance in adults.

The Journal of nutrition2011 • DOI 10.3945/jn.110.137075

How to use this page

This note summarizes one study record. Check the participants, methods, results, and limitations before applying it to training.

  • Design signal: systematic review / meta-analysis.
  • Population relevance: athlete/trained context.
  • Consistency: synthesis evidence present.
  • Practical recommendation depends on tolerance, context, and whether it protects training consistency.

ELI5

In plain language

This study was a systematic review with meta-analysis examining the efficacy of carbohydrate (CHO) ingestion compared with placebo (PLA) on endurance exercise performance in adults. (systematic review / meta-analysis; trained participants).

In this systematic review / meta-analysis, the abstract doesn’t find a clear benefit for Time to exhaustion, Time-trial performance. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: This study was a systematic review with meta-analysis examining the efficacy of carbohydrate (CHO) ingestion compared with placebo (PLA) on endurance exercise performance in adults.
  • In this systematic review / meta-analysis, the abstract doesn’t find a clear benefit for Time to exhaustion, Time-trial performance.
  • Population: trained participants.
  • Protocol cues (title/abstract): 1 h • 3 h.

Protocol

Protocol (as reported)

  • Intervention/exposure: carbohydrate, carb.
  • Dose/time/duration cues in abstract/title: 1 h • 3 h.
  • 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 may help, and who should be cautious

Who it helps

  • Athletes similar to the study population (trained participants) 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 be cautious

  • 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: systematic review / meta-analysis (placebo-controlled).
  • Population: trained participants.
  • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
  • Protocol cues mentioned: 1 h • 3 h.
  • Source: PubMed PMID 21411610 (2011) — The Journal of nutrition.

Results excerpt

What the abstract reports

This study was a systematic review with meta-analysis examining the efficacy of carbohydrate (CHO) ingestion compared with placebo (PLA) on endurance exercise performance in adults.

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

Limits

Limitations and bias

  • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
  • Reviews and consensus statements mix protocols and populations; recommendations may not match your exact constraints.
  • 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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