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Effect of timing of carbohydrate ingestion on endurance exercise performance.

PMID 8897388 (1996): 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 8897388

Effect of timing of carbohydrate ingestion on endurance exercise performance.

Medicine and science in sports and exercise1996 • DOI 10.1097/00005768-199610000-00014
Evidence C60/100
Action 2: Consider

Worth trying if it fits your goal and context.

ELI5

In plain language

This study compared the effects of carbohydrate ingestion throughout exercise with ingestion of an equal amount of carbohydrate late in exercise. (controlled study; well-trained participants).

The abstract doesn’t indicate a clear change in 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: This study compared the effects of carbohydrate ingestion throughout exercise with ingestion of an equal amount of carbohydrate late in exercise.
  • The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions.
  • Population: well-trained participants.
  • Protocol cues (title/abstract): 2 h • 90 min.

Protocol

Protocol (as reported)

  • Intervention/exposure: carbohydrate, carb (vs placebo).
  • Dose/time/duration cues in abstract/title: 2 h • 90 min.
  • 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 (well-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 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: controlled study (placebo-controlled).
  • Population: well-trained participants.
  • Comparator: placebo.
  • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
  • Protocol cues mentioned: 2 h • 90 min.
  • Source: PubMed PMID 8897388 (1996) — Medicine and science in sports and exercise.

Results excerpt

What the abstract reports

Performance in CHO-0/21 (253 +/- 10 kJ), however, was not improved compared with CON, despite higher plasma glucose levels and plasma insulin levels similar to CHO-7.

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