I'm confused

I need some definitive answers on the Heart Rate Target and exercising. I was set to buy the Polar watch but cancelled my order out of confusion!

Here’s the issue:

Allegedly if you work out at 55%-80% of your Heart Rate (other websites say a little different number) 50% of your calories burned come from stored fat. If you work out 80-90% it goes down to 35% of your calories coming from stored fat and the other comes from quickly replaced calories or gluten or something from somewhere else. So the idea is to work out at a less strenuous level and you’ll lose the fat. This is what Polar says, but of course, they are selling the heart rate monitor. And it’s what “the gym” says, but of course they’d like you to work out longer, spend more time there, purchase more services, make you feel like you need them.

Is this a conspiracy?

Other websites I found yesterday talk about yes it’s true, but if you are wanting to lose weight, then you need to work out harder, because it’s all about calories burned. While most of the calories may come from other Carbs that are easily replaceable, you burn the same amount of fat, whether it’s 30% or 50%.

Here’s just one of the many sites that you can get by googling “Myth of Fat Burning Zone.”

So what do I do? I want to get the most bang for my buck when I’m working out. I also don’t want to kill myself if #1 I’m going to hate excercising, #2 I’m not going to burn more fat.

Is there a clear answer?

(Of course, if anyone read this blog, that’d help. I did add it to my signature in the biggest loser message board, so we’ll see. I also posted a similar question there.)

UPDATE: I did get a quick response from the Biggest Loser MSG board. Which directed me to amazon.com to read an excerpt out of former BL trainer, Jillian.

She says, that the fat burning zone is a myth. And when it comes down to it, to burn as many calories as possible.

She says to work out at the 85% level, which for me would be 166. Whoa! I excercised this morning and tried to keep it to 140ish. Maybe I need to buy the watch anyway...

For further reference the book is "Winning by Losing: Drop the Weight, Change your Life" by Jillian Michaels. Pages 152-154.