Your resting heart rate is a tool that determines how efficient your heart is pumping blood. The more athletic you are the lower the rate will can be. Now the article I read said that if your RHR (resting heart rate) is below 60 or above 100 you should check in with your Doctor particularly if you have any symptoms including nausea and dizziness. On my recent to the cardiologist my resting heart rate was 64 which according to the chart I read is excellent for my age.
Definitely a result of all the training I did for the triathlons. Makes it all worth it I think.