If someone climbs from sea level to say a shallow 500m - 800m of elevation on a particular hill will there be a decrease in performance as you go up? Also will there be any benefits in doing so? I know the literature goes into detail about high altitude training at 2000m of elevation as the minimum but I want to know if there are any changes climbing from sea level up a mountain.
I’m not sure where reduced oxygen kick in but if the ramp up to 800m is long enough you’ll simply tire.
Not much drop at 800m but there is some. It also depends on how long you have been at altitude. Intervals.icu (my app) can plot power adjusted for altitude: