I remember endurance racing on Saturdays and sprinting the next day. My endurance times were typically 2-3 seconds slower per lap as I started out at a pace, didn't force my way through traffic, and then they would drop a second or two as I wore out over the course of a 45min or 1 hour stint.
The next day running 8 lap sprints i could run my lap times within a couple tenths, 8 in a row and usually faster than my practice times from the familiarity with the track.
Saturdays 2'04" to 2'07"s usually became Sundays 2'01" and 2'02"s with less effort but more concentration.
