Long-term exercise will lower the heart rate, especially long-distance running. Long-distance running is the best exercise that can increase heart muscle and reduce heart rate. I used to be a track and field athlete. At the slowest time, my heart rate was 56 beats per minute. After graduating from college for many years, my heart rate returned to about 80 beats per minute. In recent years, I have been running five or six times a week with my fitness card, and my heart rate has dropped to 58-63 times per minute.