Honestly, spend the $100-$200, go to a sports medicine place and have your VO2 max tested. They will tell you all of your zones and which ones to do on which days. Zones are just target heart rates in relation to your max heart rate before you go into complete lactic acid threshold. Your body reaches a point when your lungs can no longer metabolize the oxygen in your lungs, and your body produces too much lactic acid for the oxygenj to process. There are several zones you should work out in. The sports medicine place will tell you exactly what heart rate in relationship to your max heart rate will burn the most fat. And since most people store the most fat on their stomachs, your stomach will go down like crazy. Doing sit ups will not get rid of the fat and it can actually make you look fqatter. Reason is by doing a bunch of sit ups, you are actually building the muscles under your layer of fat. the bigger muscles will make you appear to be fatter than you really are. You really can not get into the right zone by doing sit ups because you will hit your anabolic threshhold before you get into the fat burning zone. Anabolic threshold is basically when your body starts to flood the muscles with lactic acid. once this happens, you can not exercise that muscle any longer efficiently. anyways, sorry for the long post and good luck.
