Most athletes will perform a number
of runs, often called strides prior to a running session,
particularly before one where there is to be any running
at a significant speed.
Strides, or run-throughs as
they are sometimes called, are runs over about 60m to
100m, where the speed of the runs should be about the speed you would
race an 800 or 1500m race, so a fair way short
of outright sprinting. Athletes are commonly told by
coaches to try to stride at about two-thirds of their top
speed. Basically the speed isn't too important, what is is the feeling of
running well in a controlled manner with good form, with the right stride length.