It's the age-old question. What's going to get you less wet: sprinting through the rain or walking normally? There are a lot more factors involved than you might have thought, but physics dictates that running as fast as possible will normally keep you drier, unless there's a tailwind, or, err, you're a bit thin.
Professor Franco Bocci, from the University of Brescia in Italy, worked out that it all relies on your height-to-breadth ratio, or in other words, whether you're a bit porky or not. If you're a bit on the skinny side there'll be an optimum pace, but for everyone else, running as fast as you can will keep you drier, save for puddle splashing of course.
The maths, as you might expect, is pretty complex and the whole problem is complicated by wind speed and direction too. If, for instance, the wind is blowing from behind you, the optimum running speed will be the same as the wind speed. That'll probably be quite difficult to work out, unless you're carrying one of those windspeed meters attached to your phone, of course.
So, there you have it. Sprinting will keep you the driest; although, frankly, if it's raining, the best way to keep dry is to get in the car, train or bus. Or get yourself one of those charging umbrellas, I guess. [IOP via BBC via Gizmodo UK]
Image credit: Raining from Shutterstock