:welcome great question ron. unfortunately i wondered the same thing. i'll try researching it and see what i can come up with.
I am pretty positive that you are still burning calories. I think that Target Heart Rate has more to do with getting into a "zone". If you are working harder, this may put stress on your heart, or work it harder than what you should be.. Hope this helps..
I was told by my trainer that I need to keep my THR about 117 for my age and size to burn fat, and that once I go over that I am doing a cardio workout instead of burning fat.
Target Heart Rate is based on age, sex and weight. Once you reach your THR, it means that your circulation is giving you the maximum benefits of exercise. You want to make sure that you stay within this range, if you go above it you may overwork your heart running the risk for a stroke or other heart related issues. I hope that tis helps to explain a bit :)
The machines I use have this right on them. I'll try harder to stay in the range now that I know what it is.
[color=blue:88b38e927b][/color:88b38e927b]I find that mine is 20 beats per minute right now. I would suggest talking to a personal trainer at a gym if you go to one. I found if I go over my target I know with out looking. I get kind of dizzy and tired. All I do is go slower and more steady and also I grab some water and a cool cloth on the back of the neck. I check my heartbeat and usually it slows back on track soon enough as I slow down. long term goal:145 lbs short term goal:200lbs lost so far: 30 lbs since sept 2003.