What’s target heart rate (THR)?
Anyone who has ever become involved in exercise, especially aerobic exercise, has probably heard the term “target heart rate” or “target heart range” (THR). This is a very important concept for anyone involved in an exercise program or someone who wants to start a program. Unfortunately, some exercise professionals gloss over this concept and don’t let people know just how important it is. My wife belongs to a Jazzercise group and she tells me the instructors hardly bring up the need for monitoring your THR during an exercise session. My wife wears a heart rate monitor to keep checks on her THR all the time, so I guess I’ve had a positive influence on her in that respect. I sure am glad I’m not the insurance company handling the liability insurance for this group. You see, not monitoring your THR can actually be dangerous. And, not only can it be dangerous for mature people, but it also can be dangerous for younger people, too.
So, let’s look at the concept of THR and why it is so important. Under normal circumstances, the human heart can only beat so many beats per minute. If it goes above or below these certain parameters, it usually means that something is wrong, and that’s one of the reasons we need to know what the parameters are. For the average person, a simple rule of thumb to determine your maximum heart rate (MHR) is to subtract your age from 220 (women can use 210). Example: A 60-year-old male can calculate his MHR by taking 220 – 60 = 160, so his MHR is approximately 160. A 60-year-old female would take 210 – 60 = 150, so her MHR is approximately 150. Keep in mind that this is just a rule of thumb. If you are on any drugs that might affect your heart rate, make sure you check with your doctor about your MHR and exercise. If you want to find out what your exact MHR is, you will need to have a doctor put you through an aerobic exercise test to exhaustion (a “max test”), which isn’t usually worth while for most of us. When I was in graduate school they would put me through a “max test” about once every other week to give the other students a chance to see how all the equipment worked and what they needed to do to run everything properly. They used me because I was a well-conditioned triathlete and a little stupid, too. Believe me, those tests are tough, and you don’t want to go through one unless you absolutely have to.
The reason you need to know your MHR is that it is used to determine your THR for different exercise goals. What do I mean when I say “different exercise goals”? Some people are going to exercise just to stay or get healthy. Others will want to exercise to lose weight. And still others may be exercising to increase their aerobic or anaerobic capabilities for a certain sport (swimming, sprinting, marathons, etc.).
Whatever these goals are, the THR to achieve them is going to be different. If someone wants to use aerobic exercise to help become or stay healthy, a good THR for them might be 65% – 80% of their MHR. Using our 60-year-old male whose MHR is 160, his THR for staying healthy would be 160 x 65% = 104, 160 x 80% = 128, so his range would be 104 – 128 heart beats per minute (this is measured by taking your pulse). If he wants to lose weight, he might use a THR of 60% - 70% of his MHR, because this level will burn more fat.
And, don’t forget, monitoring your heart rate isn’t only to achieve your exercise goals. It is important that you keep track of your heart rate so that if anything unusual starts to happen while you’re exercising you will know when to stop. And, again, don’t forget that if you are on any medications that might affect your heart rate, you should check with your doctor.
A really convenient way to keep track of your target heart rate is with a heart rate monitor. These can cost anywhere from about $60 to $250 or more, depending on how many bells and whistles you want. You can also take your pulse at your wrist or neck several times during an exercise session to make sure you stay within your range.
As a mature exerciser, you should exercise regularly and safely. Knowing your THR and MHR is very important, both for safety and for appropriate exercise goal setting. Learn what they are, and monitor them regularly.
Maximum Heart Rate (MHR):
Men: subtract age from 220.
Women: subtract age from 210.
Target Heart Rate (THR):
Multiply MHR by highest and lowest percentage to get the desired heart rate range.
Aerobic Exercise: 65 - 80%
Weight Loss Exercise: 60 -70%
By Thomas D. Manfredi, M.S., Online fitness coach