So, how many calories do you actually burn when you are bicycling?

Well, of course it all depends. How much do you weigh? How fast are you going? Are you riding with a parachute attached to your back…? I had always thought that this number was around 500 calories an hour then would vary a bit either way depending on how hard you were grinding it out. Though now I know for sure after coming across a nifty little chart in an article in the September 2010 issue of BicyclingMagazine. The chart below shows how many calories a 150-lb rider would burn for every hour of the various speeds of riding, which is calculated according to the Compendium of Physical Activities Tracking Guide(a standardized set of calorie-burn-measurements):

You can calculate what you, yep specifically you, burn every hour you spend on your bike. First, take your weight and divide that by 2.2(that puts it into kg). Now multiply that number by METS(metabolic equivalents, a unit of energy cost of an activity), which is listed in the parentheses in the chart. Now you have yourself an idea of how fast and how long you have to ride to eat that extra slice of pizza and beer.