How many calories does bicycling burn?
The web site I use to track calories and exercise (livestrong.com) has a variety of entries for bicycling to select from. The three I've been using are categorized as follows:
Moderate 12-13.9 mph 682 cal/hr
Vigorous 14-15.9 mph 853 cal/hr
Very vigorous 16-19 mph 1023 cal/hr
The thing is that it seems like there an awful lot of factors that would affect those numbers. For instance, I ride a mountain bike, so even if I pedal as hard as someone on a high-priced road bike, I'll always have a lower speed; if I'm going uphill I'm working VERY hard but my speed is low (and vice versa for going downhill); pavement is faster than a crushed limestone trail even when exerting the same amount of energy; and a headwind or tailwind will dramatically affect speed and the amount of energy required to keep moving. On top of all that, my understanding is that my age, height, and weight also figure into the equation (I'm 38 years old, 6' 4" tall, and about 185 pounds).
Are the figures above good enough to use assuming the variables will average out over time? I tend to just use the "vigorous" category unless I have a very good reason to move up or down the scale, which I rarely do. I don't want to cheat myself by overestimating or underestimating the calories I'm burning, so it's important to me to find a good figure I can rely on. Thanks.