Here is a little trick I use when I want to drop body fat. I eat a pretty early supper and ride an hour when I first wake up. Trick is to catch your system at the lowest point for blood sugar or available energy. Ride slow (not a race or near max HR) and when the available energy runs out your system will start burning fat. Now that your fat burning engine has kicked in it will stay kicked in most of the morningor even day. Also, this little trick kinda kick starts my metabolism when I hit a stall in weight lose. I ask my doctor before I did this. He just shook his head in a bewildered way so I didn't get a yes or no. A nutritionist would be a better person to ask on this particular advise. Works for me and also a friend of mine but may not be for everyone.