You need a citation for this? I feel the urge to shift my mask every couple minutes to get some uninhibited breathing in. Without it, I start to get a headache. Why would you think restricting air flow would not cause issues for some, especially those with higher metabolism (i.e. oxygen consumption).

Kids generally have higher metabolisms than adults, which made me feel particularly horrified about the mask mandates in schools. The sad thing is kids don't know any better, and trust older people who are telling them what to do, so there's probably many who feel noticeably worse and don't know why.

If I talk too fast, I experience the stress that the parent experiences. It sucks.