Looking for knowledge and advice about heart rates

[twosquared]

I took my second spinning class today (love it!!!). When the instructor wanted our heart rates at 80% I was usually at 95% and had trouble dropping down to 80% - think even when I was trying to ease up I wasn't. I input my heart rate zones manually on my new polar f6 - thanks all that recommended it - I'm loving it - using the resting heart rate method. I spoke with the instructor after class, and she felt that I wasn't conditioned. She wants me to concentrate in the next class on keeping my heart rate between 70 & 80% - no standing until I can maintain this for awhile.
If the heart rate is "accurate", is it dangerous to work at 90-97% for long periods of time say 30+ minutes?

Thanks for your input.

 

[pixie9]

It's my opinion that HR is really relative to each person. Yes, there are many formulas out there but they usually don't apply to fit people. Even the Karvonen formula(the one that uses resting HR) has it's flaws. If I were you, I would just key in on how YOU are feeling. Use the RPE scale(difficulty scale from 1-10) to judge where you are. Once you get to a place where you feel like you may be pushing too hard, then take a look at your HRM and note what it says. You can do this at any time of your workout to get a "feel" for what that number means to your body.

I know according to that forumula, I'm at 85% when I'm in the low 170's. I know for a fact that I can go much higher and I do so on a regular basis. For me, I need to start backing off at 180-185 depending on the day.

carolyn