As they listened, an fMRI scanner recorded the blood oxygenation levels in parts of their brains.

Source: https://www.nytimes.com/2023/05/01/science/ai-speech-language.html

“But, as conceded by the Service and Montana Fish, Wildlife and Parks at the hearing, prior oxygenation efforts have all been unsuccessful and real-world impacts have not lined up with the agency’s modeling estimates.

Source: https://www.counterpunch.org/2023/08/04/federal-court-halts-pipeline-construction-in-red-rock-lakes-wilderness/

That is nearly 1 litre less of air capacity means far lower oxygenation for the same effort.

Source: https://japantoday.com/category/sports/world-athletics-set-to-tighten-transgender-rules-lift-russia-doping-ban