Compound library
Understand what people are taking.
Browse medicines, supplements, herbs, and health foods. Each profile brings community reports and linked research into one clear view.
Browse medicines, supplements, herbs, and health foods. Each profile brings community reports and linked research into one clear view.
Stimulant that blocks the brain's adenosine ('tiredness') receptors, found in coffee, tea, energy drinks and pre-workout products. Meta-analyses of placebo-controlled trials show small but consistent gains in endurance (time trials about 2-3% faster at 3-6 mg per kg of body weight), in strength and power, and in attention and reaction time, with the biggest effects after sleep loss. The costs are just as well documented: it shortens and lightens sleep, raises blood pressure, and can trigger anxiety or panic in people prone to it. EFSA considers up to 400 mg a day from all sources, and no more than 200 mg at once, safe for healthy adults.
8 of 10 results reported a benefit, from 5 published studies.
5 studies, including a review of trials
These are the figures the studies reported, not a prediction for any one person. Where several studies measured the same thing in the same unit, we show a simple average and say so. Every individual result is listed below.
See every resultSustained physical performance — cardiovascular capacity, stamina, and oxygen utilisation during prolonged exercise.
Also known as: Caffeine anhydrous, 1,3,7-Trimethylxanthine
Every published result for this pair, extracted and audited.
These charts group published studies by what they reported and how they were run — green marks studies that reported a benefit for this pairing. Tiers run from pooled analyses of many trials (strongest) to one-off observational reports.
Direction of reported outcomes for Caffeine in endurance.
Study designs behind these findings.
Hand-selected PubMed studies, linked to the originals.
Be the first to share what you noticed with Caffeine for endurance. Why counts start empty.
Every measured outcome, one row per finding - numbers exactly as reported.
| Study | Design | n | Duration | Outcome measured | Reported result | Direction |
|---|---|---|---|---|---|---|
| PMID 38836626 2024 | Systematic review | - | - | Completion time (Time) | -0.55 SMD (95% confidence interval (CI) = -0.84 ~ -0.26, p < 0.01) | Benefit |
| PMID 38836626 2024 | Systematic review | - | - | Completion time (Time) | -0.34 SMD (95% confidence interval (CI) = -0.84 ~ 0.17, p = 0.19) | No benefit |
| PMID 38836626 2024 | Systematic review | - | - | Mean power output (MPO) | 0.44 SMD (95% confidence interval (CI) = 0.09 ~ 0.79, p < 0.05) | Benefit |
| PMID 38836626 2024 | Systematic review | - | - | Mean power output (MPO) | 0.31 SMD (95% confidence interval (CI) = -0.02 ~ 0.65, p = 0.07) | No benefit |
| PMID 19077738 2009 | Systematic review | - | - | Time-trial endurance performance (mean improvement across 33 caffeine treatments) | 3.2 +/- 4.3% | Benefit |
| PMID 36615805 2022 | Meta-analysis | 254 | - | time to complete endurance running time trials | −0.101 (95% CI = −0.190 to −0.012, p = 0.026) | Benefit |
| PMID 36615805 2022 | Meta-analysis | 254 | - | time to exhaustion in running tests | 0.392 (95% CI = 0.214 to 0.571; p < 0.001) | Benefit |
| PMID 30170953 2019 | Meta-analysis | - | - | Endurance event performance (pooled standardised mean difference, 56 comparisons) | 0.33 (95% CI=0.21, 0.45; p=1.00) | Benefit |
| PMID 29876876 2018 | Meta-analysis | - | - | mean power output | 3.03 ± 3.07% | Benefit |
| PMID 29876876 2018 | Meta-analysis | - | - | time-trial completion time | 2.22 ± 2.59% | Benefit |