We have the well known "Toxic 10" mins, but I've noticed that about 5k is my own "hump" to get over! Looking at my heart rate data on Strava it seems it always climbs steadily and then reaches a plateau between 4.5 - 6 km. Is that then point at which everything is in back in balance finally after the initial disruption of the system heart/lungs and muscle demand? I'm usually as fresh as a daisy(ish) for the first 10 mins, only getting the gremlins later towards about 5k or 25-35 mins. After that I seem to get a bedded down into a good rhythm and get the feeling I can go on and on at the same pace.
Anyone else have this delayed kind of Toxic 10 effect?
Maybe if I went hell for leather from the gun it might be more of a normal toxic 10 mins response?