Study note • PMID 1299501
Influence of carbohydrate ingestion on blood glucose and performance in runners.
Low risk + high feasibility for most athletes.
ELI5
In plain language
Ten trained male runners performed a treadmill exercise test at 80% VO2max under two experimental conditions, carbohydrate (CHO, 7% carbohydrate) and placebo (P), to determine the effect of carbohydrate… (randomized trial; trained runners).
The abstract suggests a positive effect on 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: Ten trained male runners performed a treadmill exercise test at 80% VO2max under two experimental conditions, carbohydrate (CHO, 7% carbohydrate) and placebo (P), to determine the effect of carbohydrate…
- • The abstract suggests a positive effect on Time to exhaustion, Time-trial performance under the tested conditions.
- • Population: trained runners.
- • Protocol cues (title/abstract): 5 min • 25 min • 27 min • 80% VO2max.
Protocol
Protocol (as reported)
- • Intervention/exposure: carbohydrate, carb (vs placebo).
- • Dose/time/duration cues in abstract/title: 5 min • 25 min • 27 min • 80% VO2max.
- • 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 (trained 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 (double-blind, placebo-controlled).
- • Population: trained runners.
- • Comparator: placebo.
- • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
- • Protocol cues mentioned: 5 min • 25 min • 27 min • 80% VO2max.
- • Source: PubMed PMID 1299501 (1992) — International journal of sport nutrition.
Results excerpt
What the abstract reports
“Performance was enhanced by 29.4% (p < 0.05) during CHO (115 +/- 25 min) compared to P (92 +/- 27 min).”
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.
Coaching beta
Get a plan that adapts to your life.
Join the 26weeks.ai TestFlight beta for adaptive coaching, recovery-aware adjustments, and race-week reminders.
Keep going
Performance Science Lab
Research-backed protocols and evidence grades for endurance performance — built for athletes.
Fueling performance research
Fueling is performance, not just health: the right carbs at the right time change outcomes.
Carbohydrate fueling for long runs: a protocol you can practice
Evidence-informed protocol: Carbohydrate fueling for long runs: a protocol you can practice. Practical steps, who it helps, and what to watch out for.
Time to exhaustion research for endurance athletes
A lab outcome that can still guide training: it often tracks fatigue resistance.
Time-trial performance research for endurance athletes
Practical performance outcome used in many studies: closer to racing than lab-only metrics.