I’ve written a post before about the fact that many runners think they need to buy bigger shoes for running, and why doing so actually causes more harm than good. But recently my attention was drawn to a study which set out to see whether there actually is a major increase in volume in the feet of runners.
The study was conducted in 2012, and it measured the feet of 28 runners before and immediately after a 10k run, and no difference was found!
They did note, however, that other researchers had found that shorter runs did result in an increase in foot size, and they put this down to the fact that longer distance running causes more dehydration, so losing water through sweat leads to a decrease in foot volume rather than an increase.
So although the feet may swell in the initial stages of a run, it actually decreases over longer runs – especially if the weather is hot. So there’s definitely no reason to buy running shoes that are too big for your feet – you should choose a pair that fit correctly and are comfortable for your feet.