Rode on the indoor rollers for 45 minutes after work. Used a heart monitor to help hold a good pace. With out a point of reference indicating level of intensity I have to tendency to “drift” when I am indoor spinning. My resting pulse rate has always been low. It’s gradually growing the fatter and older I get. When I used to do a lot of long distance running, my pulse when I woke used to be as low as 38 BPM. I get yearly chest xrays from my employer. The company doctor phoned me and said I had an enlarged heart based on the x-ray and told me to see a heart specialist. So I wondered if this was “it” that my heart was failing. I put off for a year seeing a doctor. So I finally did, and he scheduled a echogram to exam the heart. Well it was determined that I had Athlete’s heart that my heart was larger, the chambers were larger, and the muscle wall was thicker then normal. Mainly from years of heavy competitive powerlifting. This is not a bad thing. I powerlifted in the 80s until I qualified for the drug free nationals, and cracked a vertebrae. (see picture) I ended up having a fusion of L5 and L4 to my tail bone. I had to lay in bed for 39 days. I don’t recommend anyone lifting 500lbs at a bodyweight of 148lbs sooner of later something is going to give out. . Bicycling is more fun and better for you.