For how we live.
A small double-blind trial found a single 5.5 mg/kg dose lifted sprint power for hours, alongside higher noradrenaline and lower perceived effort — but it was 12 people, mostly men.
Trials measuring it are small but consistent: nasal breathing lowers peak oxygen uptake and feels harder at intensity. The interesting findings sit at submaximal effort, not maximal.
The famous Stanford basketball study had eleven players and no control group. Fifteen years on, sleep extension is still the best-supported sleep intervention in sport, and still barely studied.
A ten-season analysis of 3,750 matches quantifies the load argument footballers have been making. It also states plainly what it cannot show: anything about injury.
Twenty experts scored three language models on ten common questions. One model cleared the content validity bar on both topics; another scored zero on jet lag.
The first large replication project in the field found effect sizes shrank substantially on repeat, and reports that many original authors declined to engage with the attempt.