I always have a high pulse rate considering my fitness level (I was at 68), but I also tend to not be allowed to donate blood because my blood pressure is always so low.
I've wondered if the two are connected but it's one of those things I'm too lazy to investigate thoroughly.
Usually, yeah. There's a relationship between blood volume/artery constriction/heart rate in there somehow; if your BP is too low then it usually means your arteries aren't constricted appropriately enough for the volume of blood in your body, so blood doesn't rush as far with each beat, thus you need more beats to take up the slack, or something like that. That's how I've understood it.
Could also be dehydration, too (causing low blood volume). Or most likely it's just genetics. You're pretty athletic, right? I'm guessing your cardiovascular system's well adapted to handling the intense workloads, so that would factor into everything.