Originally Posted by
merlinextraligh
It all depends on how much power you put to the pedals. You could easily burn fewer calories by constantly pedaling, by simply not pedaling as hard.
What matters is how much work you do. That's determined by the time, distance, elevation change, and speed.
If you cover the same distance, over the same terrain (assuming same bike, and same position on the bike) you do essentially the same amount of work, whether you constantly pedal, or pedal and coast.
In fact, it's possible to burn more calories pedaling then coasting, to the extent you increase your speed when you pedal, and let it drop while you coast. The squared increase in wind resistance with the increase in speed, will result in an increase in the total work for the same distance over the same time.
Yes, correct...I was assuming that the OP, in stating they ride for exercise and coast "a little bit here and there," is not out noodling about, is putting in a good effort, and would continue to make that effort level if they subbed pedaling for coasting, but those assumptions aside, your point is well-taken.
I'd bet money, though, if we put a power meter on the OP's bike and had them ride their regular way and then had them make the effort to pedal continuously, we'd see a net increase in work/calories.