Pacing during the 5km run.... The biggest new runners mistake in almost all distances during a running effort is to start to fast. Heart rate at breathing at all distance from a 400m effort to a 43km effort should be greatly considered. These races are greatly different efforts but like an essay can be broken down into the same stages. (these are my words to describe how I train)
Start: especial when putting an effort against a clock it can be the tendency of the athlete to jump off the line... getting yourself too out of breath (high heart rate) can be very difficult to recover from.
Effort: this is the portion of the run after you initial start and you are getting into your pace for the run, at this time you depending on distance will need to be very time orientated and as well feel how you are feeling.
Split: you have reached the midpoint in the run. There is something called running negative splits. What this means is running the second half of the race faster than the first. The reason for this is because once you elevate your heart rate without rest, be it active or pace. You will have a tough time recovering. This is the time to stretch out the stride length and maintain pace.
Finish: this is not the finish line, this is the last ditch effort to give everything you have to get to the end... A more experienced runner will be able to stretch out for longer effort, while some athletes may prefer to hold back for a final all out explosion passing the less explosive athlete.
tactical thinking will allow for faster times, running with an experienced runner will also let you feel the pace changes which will allow for the most powerful finish