HRM?

Polar Heart Rate Monitors are pretty decent. I've gone through a few different versions but currently have the RS300x and like its simplicity and info. It tracks calories burned and so long as you program it properly it is pretty accurate - but still based on an average. If you are a runner you might want to consider one of the garmin heart rate monitors with the built in gps. I don't mind that my watch doesn't have it (i can get if if I buy the foot chip) because I usually run with my iphone and I have the Nike-GPS app which is awesome. I will also say that when I'm wearing my HRM strap - my NIKE-GPS app calcs calories as well and is always within 5 calories of my watch. If you buy the polar version you can get a flowlink that allows you to upload all your data and track it on different sites (such as polarpersonaltrainer.com). I've done a few calorie competitions at my gym and it's a neat site.

This particular Polar watch allows you to view different screens - such as your "HR Zones" that you are in while working out, calories burned, a stopwatch, current time, work out time, etc. It maintains a file on the watch until you delete it - so you can look at your past records etc right on the watch.

I use my watch primarily for my "zones" when I'm working out and to know when I've hit my anabolic threshold. The calories is secondary - and for the few competitions I enter for fun here and there. I couldn't run/workout without it.

Your AT - The point at which your body no longer is burning fat as energy source. Many people start working out and work out TOO hard - you see people going nuts on ellipticals and such but never see results. You have to build your "zones" for which you lose FAT during workouts (if that is your goal) and hitting and staying at your AT level during a whole workout all the time is not good. You likely will not see results for the effort you are putting in. AND it gets exhausting!

There's a number of ways to figure your AT - I actually have done "tests" at my gym that tell me the point at which my body converts to burning all sugar. My personal heart rate is 178 (when running, etc. - biking is about 10 bpm less than that). Basically, it's the zone when you can no longer talk, you are breathing thru your mouth, and feel like you cannot go any longer. Your muscles feel heavy, the burn is intense and mentally you are looking for a way out. Those are the signals to look for without a watch but once you have a watch you will be able to learn your zones with enough exercise so that you almost no longer "need" the watch. To improve as an athlete or to simply increase the zones for which you burn more fat - you will want to push this AT once in awhile. You will be able to exercise at a higher intensity with seemingly less effort as your threshold improves.