Runners come into the sport through many different routes. Some were runners at school, trained with a running club and kept up running through their adult lives. Others played other sports and took up running in later life. Others started to run to lose weight, get fit or support a charity.
All runners have a different physiological makeup. They have different balances of slow twitch and fast twitch fibres.
Many running books and training plans have a generic, one size fits all package that takes no account of the individual differences of each runner. So, how can we address the differences?

running coaching
I’ll give you an example.
I have two athletes who are both training to run a 40 min 10k. In order to prepare for the race, I will include race pace sessions peaking at a session of 5 x 2k, each 2 k run in 8 minutes with 60-90 seconds between runs.
Runner A has been a track runner all his life, is used to running speed sessions on a track and has progressed to road running from middle distance running. He is a predominantly speed based runner.
Runner B started running for charity and caught the running bug. He has only just started serious training but is used to running long distances at a steady pace. He is a predominantly endurance based runner.
For runner A, running at race pace will be easy but maintaining it over time will be more difficult. Therefore, the progression I would use with him would be 5 x 400m at race pace. When that can be completed easily, extend the distance to 5x600m, then 5×800 and so on.
For runner B, covering the distance will be easy but the speed presents a problem. Therefore the progression I would use with him would be to start at 5 x 1k but at a slower pace – probably 4:30 miling. When he could complete 5x 2k at this pace, I would then gradually increase the pace of the runs until he was comfortable with 5x2k pace.
This is just a simple example but there are lots of factors that effort each individual runner and need to be taken into account in planning training.
Train Smart.