Cardio8 min read
What VO₂max actually tells you
The number is real. What people claim it predicts often isn’t.
Evidence strength: 4 of 5 — Well established
Browse by system
lungs
Latest stories
View allNeuro9 min read
What actually causes fatigue?
Lactate has been blamed for a century. The evidence points elsewhere.
Evidence strength: 3 of 5 — Emerging
Metabolism7 min read
Zone 2: what’s actually happening inside your body?
Beneath the training-plan jargon sits a specific metabolic state.
Evidence strength: 3 of 5 — Emerging
Thermoregulation6 min read
Why does exercise feel harder in the heat?
Your skin and your muscles compete for the same blood supply.
Evidence strength: 4 of 5 — Well established
Neuro5 min read
Meet your sympathetic nervous system
The branch that raises the volume on nearly everything you do.
Evidence strength: 4 of 5 — Well established
Adaptation10 min read
Why two people can do the same training and adapt differently
Responders, non-responders and the trouble with group averages.
Evidence strength: 2 of 5 — Preliminary