Okay, here's a question for those of you in know - I've been using myfitnesspal.com to track my calories and riding. It works on the principle of your basal metabolic rate and assigning you a caloric amount for the day (assuming no exercise). Mine is 1350 - I'm 5'6" and 130lbs (give or take a pound or two depending on hydration status). Then you can log your exercise to essentially "earn" more calories for the day.

Now, 1350 is pretty normal for me even if I'm not counting calories. But, in the past few days I've really starting riding with a new group and based on both myfitnesspal and their cycling computers, we're burning close to 1800 calories riding 37 miles (and this is not factoring in the 20mph headwinds we ride into at ~14 mph). This morning the computer said 800 calories for a 17 mile ride at an average speed of 15mph. I'm "earning" anywhere from 2000-2500 "extra" calories a day by exercising. I'm not trying to lose weight, just get fit and see what my body can do.

So, do I need to be eating those extra earned calories? I'm afraid I won't be able to eat that much and I'm either going to get really skinny or really weak because my body has no fuel. How do you manage this incredible disproportionate calories out to calories in ratio?