It can be difficult to tell how hard you are working, especially if you are new to fitness.

Lack of results in your fitness goals can also be a sign that you aren’t working hard enough. There are many ways to help navigate exercise intensity, two of which are RPE (Rate of Perceived Exertion) and Karvonen’s Formula. The RPE scale is probably one of the
easiest to refer to, however it is only based on what you perceive and what we perceive doesn’t always match how hard we are actually working. So for that we have Karvonen’s
Formula, it is a math formula that helps to determine what your heartrate should be for
different intensities. Using these two methods together will help you to learn more about your body and how it responds to exercise.

Karvonen’s Formula: Uses your age, your resting heart rate, maximum heart rate and percent intensity.

Step 1: Your Resting Heart Rate (RHR)

Find your pulse, count the number of beats that occur in 10 seconds, multiply that number by 6. This should be done when you first wake up in the morning, before getting out of bed.

Step 2: Determine Your Max Heart Rate (MHR)

220 – Your Age = Max Heart Rate

Step 3: Calculate Target HR Range for specific exercise intensities. Repeat this for 50%, 60%, 70%, 80%, and 90%

MHR – RHR(50% + RHR) = Heartrate for that intensity

If math isn’t your thing, there is a website that can do this for you;
http://www.briancalkins.com/HeartRate.htm

An example of what your heart rate range should look like is below, along with a color coded RPE scale. Use these to help assist you for both your strength and cardiovascular training. If you want to check where you’re at in your HR Range but you don’t have a pencil and calculator handy, divide your intensity heart rates by 6 to determine what your HR would be in 10 seconds. Use that for a quick reference on the go.