The Science of Racing Flats
Is there a performance advantage wearing racing flats?
The first issue at hand is the performance advantage they confer. The logic is pretty simple: lighter shoes lead to better performance since extra weight requires your legs to do unnecessary work.
How to choose a racing flat
A racing shoe should be lightweight but still allow you to feel a “rebound” from the surface you’ll be racing on—probably pavement. And it should also not be too thin or floppy in the forefoot, lest you waste energy during toe-off.
But there’s one more thing to be aware of when considering a change in footwear for a big race: adaptation over time. Jogging a few times around the parking lot at the running store may not give you a complete idea of the effects of a lighter, flatter shoe on your feet.
If, like most runners, you usually wear “traditional” running shoes for your training, try to avoid the ultra-thin minimalist shoes that are popular with some runners, since the decrease in weight over a “regular” racing flat probably won’t make up for the effectively “harder” surface you’re running on and the decrease in forefoot stiffness in the shoe.
Definitely go for runs in your new racing flats for about the duration of the race you plan to wear them in. This means you’ll probably have to wear your flats for a long run or two if you plan to wear them in a marathon, since you don’t know yet how your body will react to your new flats after an hour or more of running.