I guess when you walk slowly in a race and weigh more, you burn more calories.
At least this calorie counter thinks so.
When I compare how much I burn when I weigh 200 pounds and take 57 minutes to complete a 5k-to when I weighed 150 pounds and it took me 30:30 minutes to complete a 5k, I get these two different numbers.
681 calories vs. 348 calories.
I guess the main benefit to being light and fast though is that you can get through a 5k faster, even if at the end you burn less calories.
This counter also says I burned around 4175 calories when I ran my marathon in San Fran. 2005, versus I'm guessing around 3030 calories for my fast and light brother-in-law Will to run his Chicago marathon. That means I could eat an extra McDonalds meal more than he did after the race! Two bad we didn't run in the same race at the same time, or that would have been fun to rub in. The slower you run, the more you get to eat.
I'm neglecting to mention that he ran his marathon in less than 3 hours, I ran mine in less than 7 hours. I think his feat is more noteworthy, but at least I get the extra burger for effort.