Heart damage leads to coronary artery disease, the narrowing of arteries that supply blood pressure to your heart. Overtime coronary artery disease leads to heart attacks and irregular heart rhythms. Damage to your heart could lead to an enlarged heart caused by forcing your heart to work harder than normal, leading to heart attack and sudden cardiac death. And lastly damage to your heart leads to heart
To calculate your target training heart rate, you need to know your resting heart rate. Resting heart rate is the number of times your heart beats per minute when it's at rest. The best time to find your resting heart rate is in the morning after a good night's sleep and before you get out of bed. Typically, an adult’s resting heart rate is 60-100 beats per minute. However, for people who are physically fit, it's generally lower. Also, resting heart rate usually rises with age.