I use the FR15 for tracking HR/speed/location during soccer (football) matches. I have arrived @ a reasonable method for me to logically break things out: Lap 1 is warmup; Lap 2 is first half; Lap 3 is halftime; Lap 4 is second half; Lap 5 is cooldown (or overtime period, if necessary); with additional Laps as necessary, however the last one is always a cooldown.
This results in an immediate depression of the lap button when the run is started. On all 'runs' there is an excessive speed registered @ the very beginning of the run (> 10 mph), but the rest of the recorded speeds are rational.