Topic

Energy and exercise

Self-rated tiredness, and what people could do in a physical test.

This page is not a ranking. Ingredients appear in order of how much we have read here.

The 10 things measured here · ingredients read against each

Read here so far: 26 questions across 17 ingredients

Beta-Alanine

Beta-Alanine and Exercise CapacityTwo sources, all measured higherModerate certainty, level 3 of 4
Beta-Alanine and Estimated VO2maxOne source, found no clear differenceModerate certainty, level 3 of 4
Beta-Alanine and Muscle CarnosineOne source, measured higherLow certainty, level 2 of 4
Beta-Alanine and Running SpeedOne source, found no clear differenceLow certainty, level 2 of 4

Caffeine

Caffeine and Endurance Performance (Time to Exhaustion)One source, measured higherModerate certainty, level 3 of 4
Caffeine and Muscular EnduranceOne source, measured higherLow certainty, level 2 of 4

Creatine

Creatine and Creatine Kinase (CK)Two sources, saying different thingsLow certainty, level 2 of 4
Creatine and Muscle strength (1-RM)Two sources, all measured higherLow certainty, level 2 of 4

Dietary nitrate

Dietary nitrate and Endurance Performance (Time to Exhaustion)One source, measured higherModerate certainty, level 3 of 4
Dietary nitrate and Estimated VO2maxOne source, found no clear differenceModerate certainty, level 3 of 4

Iron

Iron and FatigueOne source, measured lowerHigh certainty, level 4 of 4
Iron and Estimated VO2maxOne source, found no clear differenceModerate certainty, level 3 of 4

Panax ginseng

Panax ginseng and FatigueOne source, measured lowerLow certainty, level 2 of 4
Panax ginseng and Endurance Performance (Time to Exhaustion)One source, found no clear differenceVery low certainty, level 1 of 4

Tongkat Ali

Tongkat Ali and FatigueOne source, measured lowerLow certainty, level 2 of 4
Tongkat Ali and Muscle strength (1-RM)One source, found no clear differenceVery low certainty, level 1 of 4

5-HTP

5-HTP and FatigueOne source, found no clear differenceLow certainty, level 2 of 4

Ashwagandha

Ashwagandha and Muscle strength (1-RM)One source, measured higherLow certainty, level 2 of 4

Astaxanthin

Astaxanthin and Creatine Kinase (CK)One source, measured lowerLow certainty, level 2 of 4

Biotin (vitamin B7)

Biotin (vitamin B7) and Lactate (blood)One source, found no clear differenceVery low certainty, level 1 of 4

Glycine

Glycine and FatigueOne source, measured lowerLow certainty, level 2 of 4

Melatonin

Melatonin and FatigueOne source, measured lowerLow certainty, level 2 of 4

Quercetin

Quercetin and Estimated VO2maxOne source, measured higherLow certainty, level 2 of 4

Taurine

Taurine and Endurance Performance (Time to Exhaustion)One source, measured higherLow certainty, level 2 of 4

Thiamine (vitamin B1)

Thiamine (vitamin B1) and FatigueTwo sources, saying different thingsLow certainty, level 2 of 4

Vitamin B12

Vitamin B12 and FatigueOne source, found no clear differenceLow certainty, level 2 of 4

Where the sources say different things

Every side in full, because one line would have to pick one of them.

Each bar is one source’s range, drawn against the line of no difference: left of the line is lower, right is higher. Widths are not comparable between rows.

Creatine and creatine Kinase (CK)
Two sources here, and they say different things: one found no clear difference in creatine Kinase (CK) and one reported mixed results.
Low certainty, level 2 of 4The sources say different things
One source’s range, crossing no difference: these numbers fit no effect too. The sources here say different things. Randomised trial, 2018
Thiamine (vitamin B1) and fatigue
Two sources here, and they say different things: one measured lower fatigue and one found no clear difference.
Low certainty, level 2 of 4The sources say different things
One source’s range, crossing no difference: these numbers fit no effect too. The sources here say different things. Randomised trial, 2024 · 36 participants

How much of this is one source

Read from 27 sources. 22 of the 26 questions here rest on a single source with nothing yet to check them against, and on 2 questions the sources say different things.

What is still to read is kept per ingredient, not per topic, so every ingredient named above carries its own list.

Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.

The other 14 topics

This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.