From the Patient’s View by Giselle Aguiar with Personal Trainer & Lifestyle Educator, Lorrie Karn

When I first started working out regularly — besides walking the neighborhood — I wondered if I was working out hard enough. Or how fast or long did I have to workout on the treadmill to start burning fat? Yes, I want to get stronger as part of my healthy aging goals, but I also want to lose 20 more pounds. And I keep hearing “muscle weighs more than fat.”

Frustrated, I reached out to Lorrie Karn, Holistic Health Solutions resident nutritionist, personal trainer and lifestyle educator and asked her…

How do you Monitor Your Heart Rate & Determine Your Target Heart Rate when Working Out?

When looking at getting into shape there are usually a lot of questions…

  • What format should I do?
  • How often should I work out?
  • How intense should my workouts be?

All of these are valid questions. With intensity workouts being so popular, we can hone in on the intensity question… Intensity can be a subjective measurement, such as perceived exertion; which is relevant to some participants, but it can also be objective by measuring heart rate.

First let’s discuss perceived exertion

hiking bootsFitness participants who either do not want to monitor their heart rate or are on some medications (i.e. beta blockers) may choose perceived exertion. In other words, how do you feel? Many older fitness participants, such as Silver Sneakers® or Silver & Fit® will rely on a 1-10 scale of exertion. The recommendation is to refrain from entering an exertion rating 8 or higher as this may result in injury or illness. This broad stroked statement is under the presumption that many folks 65 and older are on medication that may affect their heart rate.

As far as the population that chooses to monitor their heart rates, there is a way to do this which determines different training zones. The American Council on Exercise advocates the Karvonen method of heart rate monitoring. This method is said to come within 12 beats minute (BPM) of V02Max; or maximal oxygen uptake. To use the Karvonen method, a little math is involved. The formula is:

220 – AGE – RHR (resting heart rate) = (x)
(x) is then multiplied by .60 and .80 (60% and 80%)
then the RHR is added to those two outcomes producing a range.

The outcome is the THR or target heart rate.

So, let’s look at a numeric example….

220-50 (age) – 70 (RHR) = 100
100 x .60 = 60
100 x .80 = 80
60 + 70 (RHR) = 130
80 + 70 (RHR) = 150
So the THR (target heart rate) zone is 130-150.

What does this mean?

Anything below 130 is non-aerobic. Heart rate between 130-150 is the training zone (often considered best for fat burning) and heart rates above 150 would be anaerobic.

The body can sustain in the anaerobic zone for some time, but eventually lactic acid will build up and the participant will slow down, although the heart recovery rate will not mirror the effort rate.

exercise ballsThe discussion of heart rate becomes more interesting when looking at cardiac health. When an individual works outside their THR and into the anaerobic range, the recovery time back to the THR zone is highly relevant to cardiac health. The shorter time it takes the heart to recover indicates a healthier heart. Likewise, when the bout of exercise has stopped, the time the heart takes to return to a number closer to the resting rate is indicative of cardiac health.

For those looking to burn body fat, peaking up into the anaerobic zone can be helpful when burning body fat. In the post exercise phase, the EPOC or exercise post oxygen consumption phase also is an indicator of cardiac health and metabolism.
So at the end of the day, what does this all mean?

If you’re on medication, LISTEN to your body. Enjoy your workouts, just retreat when your body requests it.

If you’re into heart rate monitoring, have fun with it. Many electronic devices can help you track your heart rate, and you can have a blast charting your numbers and how they compare to your feelings of effort.

Bottom line…. exercise and have fun!

Thank you, Lorrie!

That’s exactly what I’m doing. I enjoy going to the gym — I can’t believe I actually said that!

heart rate monitor while working outI picked up a monitor because I wanted to know how well I was doing. This particular one is not “top of the line”, but it does what I need it to do. It also reminds me when I’ve been sitting for too long, how many steps I’ve taken in the day, monitors my sleep & it’s a watch.

It all comes down to finding an exercise that you enjoy doing — so you’ll keep doing it! I like hiking and now that the weather in Phoenix is cooler, I try to hit the hills at least once a week.


What it comes down to is… if you don’t want to end up in a nursing home early, get out and move! 

Healthy aging is a choice