I'm not sure how to interpret HR except as a comparison from ride to ride. At 49 yrs and 165 lbs I average between 135 and 158 and have maxes in the 160-175 range. My younger friends who race seem to have numbers 10-20 pts higher than mine. I'm not sure if that's a measure of fitness (they are certainly fitter), or just an indication that they're pushing harder.

What I DO know how to interpret is that since I started biking regularly, my resting heart rate has dropped from mid 70s to low 60s and high 50s. Biking sure is better for my heart than walking!