Originally Posted by
OBoile
But it seems I can't follow my own advice... cycling doesn't follow this kind of linear relationship. The main resistance is air, so body weight means very little. The only time when body weight is a big factor in terms of energy expenditure is when your are going up a hill. Double the mass does not mean double the calories required.
Body size (not weight per se) can be a factor in determining drag, however.
Weight is a factor in acceleration, but that probably has really small calorie implications unless you're hitting a stop sign every 2 blocks.