I don't track my heart rate, partly because I am on a beta blocker, and that messes up the readings. I go by perceived exertion instead, but that doesn't stop me from pushing myself to the maximum.

As you get more conditioned to cardio exercise, your working heart rate range can increase. The maximum HR calculation is an estimate only. The actual HR at which you can work depends on your fitness level.

I do two types of cardio workouts- a longer moderate session (brisk walking) and a shorter intensity interval session (run 30 sec, walk 30 sec, etc). I believe both types of workouts are important when it comes to cardio vascular benefits. Both types of workouts also aid in weight loss.

The more you push yourself, the more calories you burn. 40 minutes of walking at 4 mph burns more calories than walking at 3 mph. The whole idea of cardio training is to improve, so if you have improved enough to work over the calculated HR range, then go ahead and do so.

The 'fat burning range' is just a guide. Moderate speed does burn more fat as a percentage of total calories burned, but higher speed burns more calories overall. It's the total calories burned that counts, not necessarily the percentage of fat burned.

In the long run, weight loss is more dependent on the calories in/calories out ratio. If you are not burning more calories than you take in, you won't lose weight.

Hope this helps...

The heart rate monitors on the machines often don't work properly so I wouldn't rely on them. Sometimes they can't read my heart rate at all, sometimes they tell me my heart rate is so slow I must be in a coma, and sometimes they tell me my towel has a heart rate that is above my maximum heart rate LOL.

If you want to know what your heart rate is while you are exercising, your own heart rate monitor would probably be a good investment. If you don't want to make this investment, here are links to two articles on how to tell if you are working hard enough without knowing your heart rate:
Talk Test: http://exercise.about.com/od/cardiow...getheart_7.htm
Perceived Exertion Test: http://exercise.about.com/cs/fitness...ceivedexer.htm

And while I'm posting links, here is one to an article that talks about how intense your cardio workouts should be: http://exercise.about.com/cs/cardiow.../aa022601a.htm. There are lots of different opinions about this so I'm sure you could find an article somewhere that contradicts everything in this article. I've pretty much given up trying to figure it out. Personally I'm always at about a 7 on the Perceived Exertion Test when I do cardio. When I work out with my trainer, I'm usually at a 7 and once in awhile an 8. I don't seem to have done any damage to myself and I've certainly lost weight.

- Barbara

Thanks for the links, Barbara!