Defined-use recommendation
Caffeine for performance
Best supported for
Improves endurance performance on average.
Why we selected it
Known caffeine content is useful. No supplement brand is selected.
Do you actually need it?
Optional if you tolerate it and protect sleep; ordinary coffee may be enough.
Safety before use: Insomnia, anxiety, tremor, palpitations and interactions. Pregnancy and medication use require their own limits. Count all caffeine sources and avoid high-dose stacking.
Who may benefit & who can skip it
You might benefit: Healthy adults who tolerate caffeine and want an occasional performance aid.
You probably do not need it: People who dislike the effects, have sleep problems or already obtain enough from ordinary coffee.
What to look for & important limitations
What to look for
Known caffeine content and conservative single-dose control. Research often uses 3–6 mg/kg, but that is not a blanket instruction. Count all sources, protect sleep and avoid bulk pure caffeine powders.
Important limitations
The ISSN review finds the most consistent support for aerobic endurance, with less consistent strength/power effects. Individual response and sleep cost can outweigh a small performance gain. A capsule is not necessary to obtain the effect.
Ordinary or free alternatives
Low priority for a broad health Shelf. Keep as a conditional evidence guide; do not sell the impression that everyone needs a stimulant.
The evidence & product checks
The evidence
What is checked about the product?
No commercial supplement is selected. Coffee is a reasonable alternative; concentration varies. More caffeine does not reliably mean more benefit.
Intervention evidence, product-label checks and independent testing are separate. These examples are not claims that one brand is scientifically best.