If an athlete usually runs for 60 minutes, then the first time they run 1hr30m it becomes a new stimulus. This can be characterised by tiredness, sore or stiff muscles. After a few weeks the body gets used to the distance and therefore it is no longer a stimulus. The same athlete might then extend the distance by running 2hr, 2hr15, and then 2hr30. If the athlete is not running at their goal race pace then they are missing out on the specific intensity part of training. There are limits to extension. Increasing extension without correct intensity is not effective. Good coaching will give you that balance.

This is the speed of the run. If training for a specific half marathon or marathon time you need to be able to run at least 15 km at your goal pace in training. Once you can do that you move to (for a marathon) 25, 28, 30 and 35km. This does not just happen over a few weeks. The timeframe is dependent on your goal and what you are able to run right now. Well coached runners are not concerned about finishing. They are concentrating more on the pace. Success in the previous months training gives them the confidence that they can compete at the level required.

Athletes rely on easier running days to recover. After a long hard run or an intense interval session they should have between 2 and 5 days of recovery runs. What is important is that the body is recovering, regenerating and improving. Depending on the level of fitness, beginner recovery runs can start at a complete day off but for elite runners it might be two longer runs on the same day. The recovery runs might be easy for them but they are often a lot longer and faster than the average runner can achieve. As key training days become more intense the number of days recovering are also increased. It is a gradual process specific to each athlete. As you get older you actually don’t need to run as much as eventually you reach your aerobic capacity.