I've been smoking ganja for 40+ years, I'm 54 this year and still playing soccer, hockey and snow board through the winter, ride my bicycle and do some running between sports seasons. I haven't found it affects me but that's just me. I've gone through years or running, done marathon's, triathlon's and sports throughout my life which probably makes a big difference. I try and vape more often now and when I smoke it's in a pipe typically, small amounts. It's all about genetics I think though, I've had scans/x-rays where the tech was sure I was a non-smoker, lucky genes I guess. Cancer's about genes too, I've lived fairly healthy, eaten well, excersize more than most people and certainly more than most people my age now, stillI got cancer about 5 years ago and it had nothing to do with the smoking, they figure it was triggered by stress and a bacterial infection I got from a fly bite, go figure.