Heart Rate Monitoring advice

work out your lactate threshold and base your zones around that rather than your max heart rate

the fat burning zone is not a myth, its scientifically proven that you burn a higher % of fat in this zone whilst exercising, its an important point that we are talikng about a ratio of fat to carbs not ammounts of fat here, you could well burn more fat by going a bit harder.-however it is not as simple as that. the body is a complicated machine, from all the reading i have done on the matter (which is a lot believe me) it comes down to a very simple equation:
to lose weight you have to create an energy deficit i.e. burn more energy that you put into your body, it makes very little difference what zone you do it in.
the simplest way to explain this: becuase our bodies are so efficient at converting energy you could train in the fat burning zone and burn fat, but as soon as you eat your fat stores wll get replenished, whereas if you trained in a higher zone you would be mainly using carbohydrates, but when you eat your body uses the energy that it has lost rather than converting it to fat. so its swings and roundabouts to which zone you train in and each has its advantages and dissadvantages.
the amusing thing to me is that the lower the heart rate the higher % of fat you burn, there fore sleeping is the best way to lose weight.

Who said lighter people live longer anyway?? lol - only kiddin'

I agree that the FBZ isn't a myth. I've seen test results from pro riders who burn fat effiiciently up to about 90% of their max heart rate. That's how they win National and World XC titles. The issue is that everyone seems to think that riding slowly isn't going to burn fat, get impatient and then carry on riding like normal(and carrying on wearing the monitor to prove they've earned the calories they throw in their stomach after a days trail riding).
You have to also change your diet so that you aren't eating a tonne of sugar that your body will have access to all the time. Lower GI-valued foods will force your body to burn fat more efficiently.

The more efficient you can do a few of these things, means that before you know it you won't be craving a can of coke and a chocolate bar after a 2 hour midweek riding session.

You don't want to do a year of fat burning training, that'd be boring(but would prepare you for a mega endurace race). So do 4-8 weeks of it, keeping the heart rate in those boundaries and not above. Then after those 8 weeks start to add intensity to your rides, and before you know it, it'll be spring 2011 and you'll be faster than your riding buddies.

I think what someone was trying to say is that once your energy stores are depleted(glycogen from muscles) from exercising at a high heart rate then your body will start to use muscle as an energy rather than transform fat to energy, this is because muscle is in a simpler form for your body to use it. In order to make fat a useful fuel it takes a bit of energy which your body won't sacrifice if you have an elevated heart rate.

Be careful when you do a max heart rate test as they're very demanding. You can't get your max heart rate from a website.