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Effects of Energy Gel Ingestion on Blood Glucose, Lactate, and Performance Measures During Prolonged Cycling.

PMID 31977833 (2021): 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 31977833

Effects of Energy Gel Ingestion on Blood Glucose, Lactate, and Performance Measures During Prolonged Cycling.

Journal of strength and conditioning research2021 • DOI 10.1519/JSC.0000000000003297
Evidence B71/100
Action 1: Default

Low risk + high feasibility for most athletes.

ELI5

In plain language

Kozlowski, KF, Ferrentino-DePriest, A, and Cerny, F. (randomized trial; trained cyclists).

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: Kozlowski, KF, Ferrentino-DePriest, A, and Cerny, F.
  • The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions.
  • Population: trained cyclists.
  • Protocol cues (title/abstract): 30.96 mg • 14.82 mg • 15.85 mg • 2 hours • 15 minutes • 30 minutes.

Protocol

Protocol (as reported)

  • Intervention/exposure: carbohydrate, carb (vs comparison group).
  • Dose/time/duration cues in abstract/title: 30.96 mg • 14.82 mg • 15.85 mg • 2 hours • 15 minutes • 30 minutes • 45 minutes • 60 minutes.
  • 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 cyclists) 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.
  • Population: trained cyclists.
  • Comparator: comparison group.
  • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
  • Protocol cues mentioned: 30.96 mg • 14.82 mg • 15.85 mg • 2 hours • 15 minutes • 30 minutes • 45 minutes • 60 minutes.
  • Source: PubMed PMID 31977833 (2021) — Journal of strength and conditioning research.

Results excerpt

What the abstract reports

The purpose of this study was to determine the effect of carbohydrate energy gel ingestion schedules (e.g., manufacturer's recommendations vs.

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