I am an active 21 year old. I regularly go to the gym regularly and have a physically demanding job. I eat well, carefully controlling my portions and nutrition. I drink plenty of water. I don t smoke, or use recreational drugs, and I drink only very occasionally. I use caffeine very rarely as I have a low tolerance for it. I don t use caffeine at all on days I work out, as I find caffeine makes me too jittery to be productive. I have a BMI of 23.4. I am in the best shape I have ever been. My concern is this: I have a resting heart rate of a rather boring 62 bpm on average. However when exercising to well within my tolerance (I can talk, but not sing), my heart rate climbs to around 220 bpm. Is this a cause for concern? I show no other symptoms.