I get many questions from new runners about how fast they should run their training runs. The common mistake is to assume that faster is better. Inexperienced runners generally have the idea that the only way to run fast in races is to run fast during training runs. However, this belief will usually lead to injuries. Instead of running training runs fast, focus on limiting your pace so that you could carry on a conversation if a person was running next you. In order to gain speed for races, focus on running fast during speed workouts such as fartleks and tempo runs.
The purpose of the daily training run is to develop the cardiovascular and muscular systems that constitute the foundation for fast running. In order to develop these parts of the body in the most efficient way possible, and without increased injury risk, it is very important to run at a pace that works these systems without too much strain on the body.
That is why the conversation pace is a good indicator for proper running. If a runner is able to converse while running, he or she is exercising at an aerobic (as opposed to anaerobic) level and the body does not enter into oxygen debt.
I do want to emphasize that running at conversation pace is only for the ordinary training run. If you are going to run a fartlek, tempo run, hill workout, or track interval, then you obviously must run much faster than conversation pace.
Photo courtesy of Gruban
