The Library
The parts that are not a movement or a muscle: what training actually changes, how long it takes, and which of the things you have been told hold up.
14 articles
How the body responds
- Bone, loading and density Bone is living tissue that responds to being loaded — which makes resistance training one of the few things that acts on it directly.
- Energy systems in plain English Three ways your body pays for movement — and they are not three switches that flip, they run together all the time.
- Muscle fibre types, and why most of what you have read is oversold Fast and slow fibres are real. Almost everything built on top of them — rep ranges, testing, training for your type — is not.
- Sleep, recovery, and the part nobody sells you Adaptation happens between sessions, not during them — which makes the unglamorous half of training the half that decides the result.
- What actually changes when you train Strength arrives before size, and for the first stretch you are not building muscle so much as learning to use it.
- What soreness is, and what it is not Delayed muscle soreness is not lactic acid, not a measure of a good session, and not a reliable signal of anything much.
- Why tendons adapt slower than muscle The most useful single fact about getting injured — your muscles get strong faster than the tissue attaching them to bone.
Training concepts
- How to start again after a long time off The main risk is not that you will do too little — it is that you will remember what you used to do and attempt it.
- How to warm up, and what warming up does Warming up is worth doing and it probably does not prevent injuries — those are two separate claims and only one of them holds.
- What "form" means, and why most form advice is overconfident There is no single correct way to perform a movement, because there is no single shape of person performing it.
- What progressive overload actually means The one principle underneath all training — and it is a great deal broader than adding weight to the bar.
- What the evidence says about stretching Stretching increases the range you can tolerate, mostly by changing your nervous system rather than lengthening tissue — and it does not do most of the other things attributed to it.
- Why spot reduction is not a thing The belief that working a body part removes the fat over it — the single most profitable false idea in fitness, and the one this whole site is built to refuse.
- Why this site does not print calorie numbers Every "calories burned" figure you have been shown was produced by an estimate with error bars nobody displays.