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Study note

Single and combined effect of beetroot juice and caffeine intake on muscular strength, power and endurance performance in resistance-trained males.

PMID 40369047 (2025): caffeine, beetroot — Time-trial performance, Time to exhaustion (study note for endurance athletes).

Updated Jul 22, 2026

Read the study note

Study note • PMID 40369047

Single and combined effect of beetroot juice and caffeine intake on muscular strength, power and endurance performance in resistance-trained males.

Scientific reports2025 • DOI 10.1038/s41598-025-02021-y

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: randomized trial.
  • Population relevance: athlete/trained context.
  • Consistency: single-study evidence.
  • Practical recommendation depends on tolerance, context, and whether it protects training consistency.

ELI5

In plain language

To examine the single and combined effect of acute beetroot juice and caffeine supplementation in muscular strength, power, and endurance performance. (randomized trial; 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: To examine the single and combined effect of acute beetroot juice and caffeine supplementation in muscular strength, power, and endurance performance.
  • The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions.
  • Population: trained participants.
  • Protocol cues (title/abstract): 3 mg/kg • 180 min • 60 min.

Protocol

Protocol (as reported)

  • Intervention/exposure: caffeine, beetroot (vs placebo).
  • Dose/time/duration cues in abstract/title: 3 mg/kg • 180 min • 60 min.
  • Outcomes: Time-trial performance, Time to exhaustion.
  • 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 supplements.
  • Athletes who can measure Time-trial performance, Time to exhaustion 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: randomized trial (placebo-controlled).
  • Population: trained participants.
  • Comparator: placebo.
  • Outcomes measured: Time-trial performance, Time to exhaustion.
  • Protocol cues mentioned: 3 mg/kg • 180 min • 60 min.
  • Source: PubMed PMID 40369047 (2025) — Scientific reports.

Results excerpt

What the abstract reports

In BS, muscular strength/power showed a supplement-by-load effect in V(mean) and W(mean) (P < 0.05, eta(p)(2) = 0.167-0.173), with caffeine increased compared to placebo at 75%, 90% and 100%1RM (9-25%, P < 0.005, g = 0.51-1.47); while in muscular endurance, significant differences were…

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).
  • 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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