Five years ago I was in the gym working out; I was 62. I had a nice routine 4 days a week mix of cardio and strength training. One day I increased my weights by 5lbs . Finished my work out and drove right to the neighborhood ER. I had triggered an SVT - basically a racing heart beat. The Dr was speechless, when I told him. He's used to telling old heart patients, exercise more, drink less alcohol, don't smoke etc. Not me, all he could say was "you shouldn't have increased your weights." He got me fixed up and then we had a good laugh. Thirty years ago this wouldn't have happened.