I have been training with a heart rate monitor. When I run at my race pace, my heart rate is usually between 168-172. I am 32, 5'5" and weigh 134 and I have been running for over ten years. According to some charts, I am working at a high intensity, but I don't feel out of breath or tired. Any thoughts?

Wow, if that's your heart rate at race pace for Ironman, and it's comfortable, then you might just have a very conditioned body with a high max heart rate upwards of 200. Have you ever done a Max Heart Test?

Usually at an Olympic distance I'm running at about 80-90% of max. For longer distance like a half, I'm closer to staying in the 75-80% range. But that's me, I know where my limits are and if I cross my LT threshold to early in a longer race I'm pretty much toast.

Each of us is different and can tolerate different exersion levels. If you're in the higher 90% range and not bonking and are comfortable, then I'd assume it's o.k.

This isn't really about heart rate zones but it is about heart rate, so i thought i would post it here :) . I was reading somewhere about how it is useful to establish you resting heart rate from measurements taken when you wake up first thing in the morning. So this morning i did that. I took my pulse for 15 secs and multiplyed it by 4. But this gave me a heart rate of 36bpm!! Is this a little on the low side?

Thanks

OK, I haven't completed an IM yet, but that's my rate for 1/2 marathon and 1/2 IM distance. I have not completed a Max Heart Test...how can I do that?

Star, that's till very good for half distances. I would expect doing a full you might consider lowering it. Figure you'll be out there for more the twice as long, so could you sustain that effort for 10+ hours?

Here is a good article on different methods to calculate your zones.
http://www.trifuel.com/triathlon/triathlon-training/finding-your-maximum-aerobic-heart-rate-000574.php

On calculating max heart rate, Do 20 minutes of warm up, light run to get you heart going. Then find a gradual incline about 1/4 mile long. Run this incline at an all out effort and check your heart rate at the top. Do this severall times and you should be able to get an a good measurement for you max to plug into some of the formulas in the article above.

Shiner - that is low, but you could be very fit or have a naturally low heart rate. Try using a heart rate monitor if you have one, it'll give you a more accurate measurement. To give you an idea, many pro ironman athletes are at that low level, but usually after years of training.

Thank you for the tips! I'll give it a try as I move towards my goal...