Liza;

Kelowna girl is correct. As you exercise, the heart becomes more muscular and efficient, therefore it doesn't have to work as hard, thus your RHR. My RHR is 50 (I'm 48) When I exercise, I also can get it very high, quickly - my du last year, during my run - I was 196. But it plummets quickly when the intensity drops.

My FD made me go for ECG, heart is fine, so I don't worry about high HR.