Resting Heart Rate.

Can I use a Heart rate monitor to know my resting heart rate? And If the answer is yes, how should I do that?

Or should I use a other methodes?

Yes, put your HR monitor on when you first wake up in the morning. Lay down and relax for a few minutes while recording HR and look at the lowest steady value.

Thanks frenchyge.

If you have a HR monitor which can be downloaded into the computer, you can put in on while you sleep and get a pretty good estimate.

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I haven't such advanced HR monitor.

If you have a clock that has a seconds hand on it, I'd count your pulse for 10 or 15 seconds and multiply accordingly. Your pulse will be slightly higher just after you wake up than it was when you were sleeping.