Study note • PMID 37450275
Effect of isolated and combined ingestion of caffeine and citrulline malate on resistance exercise and jumping performance: a randomized double-blind placebo-controlled crossover study.
Worth trying if it fits your goal and context.
ELI5
In plain language
The aim of this study was to explore the isolated and combined effects of caffeine and citrulline malate (CitMal) on jumping performance, muscular strength, muscular endurance, and pain perception… (randomized trial; n=18 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: The aim of this study was to explore the isolated and combined effects of caffeine and citrulline malate (CitMal) on jumping performance, muscular strength, muscular endurance, and pain perception…
- • The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions.
- • Population: n=18 trained participants.
- • Protocol cues (title/abstract): 5 mg/kg • 60 min.
Protocol
Protocol (as reported)
- • Intervention/exposure: caffeine (vs placebo).
- • Dose/time/duration cues in abstract/title: 5 mg/kg • 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 helps, and who should skip it
Who it helps
- • Athletes similar to the study population (n=18 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 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: n=18 trained participants.
- • Comparator: placebo.
- • Outcomes measured: Time-trial performance, Time to exhaustion.
- • Protocol cues mentioned: 5 mg/kg • 60 min.
- • Source: PubMed PMID 37450275 (2023) — European journal of nutrition.
Results excerpt
What the abstract reports
“However, there was no significant difference between isolated caffeine ingestion and caffeine co-ingested with CitMal, and isolated CitMal supplementation did not have an ergogenic effect in any outcome.”
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.
Supplements performance research
Supplements are optional. Only a few reliably move the needle, and context matters.
Caffeine for endurance performance: a practical protocol
Evidence-informed protocol: Caffeine for endurance performance: a practical protocol. Practical steps, who it helps, and what to watch out for.
Time-trial performance research for endurance athletes
Practical performance outcome used in many studies: closer to racing than lab-only metrics.
Time to exhaustion research for endurance athletes
A lab outcome that can still guide training: it often tracks fatigue resistance.