This little rule has been knocking about for along time and for those of us who have put on a few pounds over Christmas and are now desperately trying to shed that unwanted weight, a little reminder is called for.
Finding our ideal running weight is crucial to our running performance but just how much does weight affect speed? Just how thin should we be and how will it affect our running and racing? There is some evidence that suggests we run two seconds per mile faster for every pound of weight we lose until we reach our ideal weight. Then we start running slower as our body doesn’t have the strength it needs to make us run our fastest.
Losing a pound or two doesn't mean much over a single mile, but when this is multiplied over a 5k or 10k race we really start to see the advantage of being that little bit lighter.
For example. Ten pounds is the equivalent of 20 seconds per mile, which over 5K is more than a minute. In a 10K it is over 2 minutes and nearly 4.5 minutes in a half-marathon. Even for some of our more finely tuned athletes shedding a couple of pounds could take 30 seconds of a 10k, perhaps enough to break the 40min barrier or even earn a place on the podium.
There are of course many other factors that affect our running speed but for those of us that are carrying a little extra weight losing a few pounds will not only get us across the finish line a bit quicker but it will also help to reduce the risk of injury and improve our biomechanics.