Originally Posted by
david58
That's kind where I lean - in being somewhat conservative. If I figger 35 calories per mile, do 18 miles in the hour (per the Cateye), it comes out about 600. So with the 500 number I don't get relaxed on the intake.
That is the way I would figure it. When I am on a trainer, I wear a heart rate monitor. You can go on a rode ride with a heart rate monitor and get an idea of how fast you are going on flat terrain for a given heart rate. Knowing your heart rate on the trainer can yield an approximate miles ridden for the session. You can use one of the internet sites to convert miles and mph and rider weight into calories expended.
The thing is that calories expended is just an estimate and it probably has error bars of about plus 50% and minus 33%. One figuring a calorie balance, if you are careful and keep a food log and weigh or measure your food consumption and what you take in, you can get a pretty accurate idea of calories in. Figuring calories expended is a much fuzzier figure. Direct measure of calories expended is pretty much for laboratory settings only.