Most people know that one of the best ways to ensure you are getting the most out of a cardiorespiratory workout is to monitor your heart rate, making sure to keep it in your target heart rate zone.  However, what most people don’t know is how exactly to find your target heart rate zone.  Luckily Dr. M J Karvonen did the number crunching for us back in 1957 and gave us what we so cleverly named, the Karvonen method.  His method is now the golden standard for finding the most accurate target heart rate based off of age and resting heart rate.   His formula looks a little something like this:

HR_Target= ( (HR_Max– HR_Rest) * %Intensity ) + HR_Rest

_ Trust me, upon first glance I decided I would much rather read the entire Harry Potter series in at least three of the 67 different languages printed before applying any energy into figuring out that formula.  However, I soon remembered I really don’t know any other languages aside from key words such as beer, bathroom, and a wide assortment of swear words so I ventured into learning the formula and realized it really isn’t as difficult as it appears. Here’s what you need to know:

Resting Heart Rate (HR_rest):  As the name suggests, this is your heart rate when you are at rest, meaning you have not recently performed any vigorous activity.  The average person’s resting heart rate is anywhere from 60 to 100 beats per minute.  Prime athletes at the top of their game have been known to have a lower heart rate closer to 40 beats per minute.  This is because the more conditioned your heart is, the less it has to work to pump blood and oxygen throughout your body.

Maximum Heart Rate (HR_max): Your maximum heart rate is the highest heart rate that can be safely obtained and held during exercising.  There are several formulas for obtaining maximum heart rate, some including standard deviation and some not.  The  most commonly used formula is 220 – Age.  This is the formula we will be using.

Target Heart Rate (HR_target): An individual’s target heart rate is the desired heart rate range they want to be in when performing a physical activity.  This range is calculated by figuring the intensity of workouts in relation to your resting and maximum heart rate.  The average target heart rate zone is somewhere between 60-90%.   A beginner should strive to achieve a heart rate somewhere in the 60% range while only advanced athletes with a doctors go ahead could strive for the 90 percentile range!

Now that we know the crucial terms, let’s decipher the above formula in Karvonen’s method.

Step 1: Determine your resting heart rate

• Place your index and pointer finger on your carotid artery of your neck (located between the jaw and collar bone), and count your pulse for 60 seconds.  You may also count for ten seconds and multiply the beats per second by 10, however the longer you count the more accurate you will be.  Therefore I recommend counting for the full 60 seconds.
• Be sure to do this three days in a row right as you wake up in the morning while your heart rate is still truly at rest.  Alarms tend to scare the bajeezus out of us when we’re in a deep sleep so if you have to set an alarm in the morning to wake yourself up, be sure to allow your heart rate to come back to it’s resting rate before attempting to measure the resting heart rate.  Otherwise you will have some crazy and potentially dangerous results!

EXAMPLE:

Day 1: 70 bpm

Day 2: 68 bpm

Day 3: 69 bpm

 (70 + 68 + 69) / 3 = 69 bpm

Step 2: Determine your maximum heart rate.

• Simply subtract your age from 220.  Let’s use an example of a 27-year-old individual.

EXAMPLE:

220-27 = 193 bpm

Step 3: Plug in your resting heart rate and maximum heart rate with the desired intensity of between 60-90% into Karvonen’s formula.

HR_Target= ( (HR_Max– HR_Rest) * %Intensity ) + HR_Rest

Lower Intensity = 60%

Higher Intensity = 90%

HR_max = 193 bpm

HR_rest = 69 bpm

Lower Target Heart Rate (60%) = [(193 – 69) x .60] + 69 = 143.4

Upper Target Heart Rate (90%) = [(193-69) x .90] + 69 = 180.6

So the target heart rate zone for this well trained 27 year old athlete training at 60-90% of their ability would be between 143 – 180 bpm.  Just keep in mind, training at 90% intensity is for advanced athletes only!