I would normally only buy/wear one pair of shoes at a time, but after talking to the guys in my local running shop, they suggested two pairs of shoes, one for training and running in and the other for racing in. I genuinly believe he was not on a sales pitch, they're not like that. I did buy the 2 and next weekend will see the test of the racing shoes. Looking at the make up of them and the rubber used on the sole compared to my training shoes, it makes a lot of sense. I suppose it depends on what you're inro running for. I am in it to get fit but also get quicker, over time. Worth bouncing the idea around to a few people, see what response you get and make your own mind up!