The lactate paradox, where lactate levels are lower during exhaustive exercise at lower altitudes compared to sea level, may be due to the brain reducing oxygen supply to muscles when overall oxygen levels drop.

“the picture that that makes sense to me is is that it's these things are not just about how much oxygen is making it to the muscle it's also like what is the what is your brain oxygen level and so you're you're getting these other circuit breakers that are starting to come down that aren't even on this path from mouth to lungs to to blood to to muscle there there's other factors that are saying whoa wait a second Oxygen's getting a little low so we're going to actually cut off the supply to the muscles or reduce it in order to make sure that we don't get stupid”