^^ i cant back it up with a study bro but thats what ive always heard. I think as long as your in the 70's your pretty good. Id like to see mine get back into the 60's but low 70's im pretty happy with.
Just think about it though, your heart has to beat so hard to push blood around a 170 pound guy. If you put on 50 pounds now it has to push blood through 220 pounds worth of tissue etc. It would just make since to me if your heart push so much blood in one beat so it has to beat a bit faster to do the same amount of work. Make since? It kinda does to me but im tired and i just explained that like a 3 year old lol. catch you guys in the morning.