A common question the exercise staff of the JRMC Wellness Center receives is: “Where should my heart rate be when I’m working out?” I am always encouraged by the question and believe the reason it is asked so often is three fold. First, we live in an “information” culture. If there is info to be had, people want it. Secondly, most current cardiovascular exercise machines directly measure an exerciser’s heart rate with a simple touch. And last, wireless heart rate monitors
– chest straps that transmit heart rate to a receiver worn on the wrist
– are less expensive and more common than ever.
The frequency with which the heart beats is referred to as heart rate or pulse rate. The number is expressed in beats per minute (BPM). The more strenuously the body works, the more frequently and forcefully the heart beats. We must know a few pieces of information before we are able to determine what heart rate we should strive to attain during our cardio workouts.
First is resting heart rate (RHR). Resting heart rate is most accurately measured in the morning, immediately after you awaken (without an alarm clock). Use the first and second fingers of one hand to find the pulse on the underside of the wrist (thumb side), or just to the side of the windpipe. At the least, count the number of beats for 15 seconds and multiply that number by 4, or you can simply count the number of beats for an entire minute. Take the measurement for a few days. If the numbers vary by more than about 5 beats per minute, take the average of 7 day’s measurements. Normal resting heart rates range from 60 to 100 BPM. Generally, lower resting heart rates indicate more efficient heart function and better cardiovascular fitness. A well-trained athlete may have a resting heart rate closer to 40 BPM. It is also important to note that a variety of medications, especially those for heart disease, high blood pressure, and diabetes, may affect your heart rate. If this applies to you, consult your doctor before beginning an exercise program.
At the other end of the spectrum is maximum heart rate (MHR), the most rapid rate at which your heart will beat. True maximum heart rates can only be safely determined with a graded exercise test administered by a physician. In light of the cost and inconvenience of this fact, researchers tried for decades to determine how best to guesstimate maximum heart rate. I use the term “guesstimate” because that is what the number derived is … a best guess. The most recent formula to determine MHR reflects the past 25 years of research on the topic. The equation: 208 – (.7 x age) is more accurate than previous formulas, but is still an educated guess.
The difference between MHR and RHR is an individual’s heart rate range (HRR). The greatest long-term health benefits at the lowest risk of an acute cardiac event (think: heart attack) are available when an individual works in his or her “target heart rate zone”. This is a general reference to the area between 60% and 80% of your maximum heart rate, while taking into account your resting heart rate. To find the lower threshold of your zone multiply .6 by your HRR, then add your RHR. The upper range is determined by multiplying .8 by HRR and adding RHR.
Individuals who haven’t exercised in a while should start a program at the lower end of the range (or lower if recommended by a physician). The upper end of the zone may be utilized by individuals who have a base level of conditioning, who want to burn more overall calories in pursuit of body fat loss, or who are training for some type of event.
And there you go. One more excuse down! Let’s get to work!
The JRMC Wellness Centers, located in Pine Bluff and White Hall, offer a variety of fitness options for all ages and interests. Free weights, machines, cardio equipment, personal trainers and a full schedule of Les Mills classes are.