When many people go for a run, they opt to bring along a heart rate monitor. During their run, the monitor shows them that their heart rate has increased dramatically. They may wonder if this is normal for them, and often express concerns regarding their heart or pace.Your heart will beat faster as soon as the intensity of your exercise increases. Your heartbeat is measured in beats per minute (BPM). and is used to indicate exercise intensity. Your maximum heart rate does not change with your fitness, unlike your resting heart rate. It decreases as you grow older. You must also remember that maximum heart rate varies with different sports because lots of muscle groups are used. Running uses the most muscle groups and therefore causes the biggest maximum heart rate in participants.If you have any major concerns or feelings, or if you are over 35, it is important you visit a physician. You can discuss your health history and exercise programs with them, and they can examine you or make you take a “stress test”. This can be done on a treadmill. It starts on an easy level at first, and then increases in intensity every three minutes by upping the incline and speed. Your heart rate and blood pressure will be measured throughout. When the intensity level increases and your heart rate doesn’t, you are at your maximum and may feel like you want to stop. You must not exceed 85% of your maximum heart rate when exercising.Here is a table that indicates the best ways to estimate your heart rate. However, there is a 15-20 bpm margin of error in these estimates: Formula Men WomenAge adjustedMHR = 220 – ageMHR = 226 – ageBall State UniversityMHR = 214 – (0.8 x age)MHR = 209 – (0.9 x age)Londeree & MoeschbergerMHR = 206.3 – (0.711 x age)MHR = 206.3 – (0.711 x age)Miller et alMHR = 217- (0.85 x age)MHR = 217- (0.85 x age) You can use the results from your heart rate monitor and combine them with your predicted level for each workout. This will help you to find your training zones. Record every heart rate, whenever you feel a workout is easy, hard, or when you are racing. Then you will have your heart rate for each type of run. You will then start to see a pattern and have a better idea of what is normal for you.Keep an eye on your resting heart rate too, as this tells you more about your body. Record your heart rate before you get up every morning, and you will see your resting heart rate decreasing as your fitness improves. However, if your resting heart rate increases up by 10 bpm or more, record this too. This could be a sign of stress or fatigue, so you may need to make some changes to your lifestyle. You could go for a short, easy run, stretch more or improve your eating habits until your heartbeat returns to normal.Running is good at helping us learn about our bodies, so we must listen to them and the signals they give us. The most important things to note are to know your limits, take proper care of yourself and seek medical advice for peace of mind.