Po's notes: How to use a heart rate monitor?

Heart rate, a good indication of the intensity of a workout, helps an athlete to train properly and more efficiently. Athletes determine more accurately whether they are training in a “hard” or “easy” zone by reading the numbers instead of just guessing.

Before we can calculate the target zones of different workout intensities, we first need to understand these terms: Maximum Heart Rate (MHR) and Resting Heart Rate (RHR).

What is Maximum Heart Rate (MHR)?

MHR is simply the maximum number your heart can beat per minute. One’s MHR is pre-determined and won’t be affected by one’s fitness level; however this number gradually declines as people age. There are many formulas to help people estimate their MHR, among which this one is probably the most well-known:

(1) MHR = 220 – age;

But remember, this formula only offers an approximation. Some people freak out when their monitor shows a larger number than that calculated using (1); however, this simply means you have a higher MHR number than average.

If you want to take full advantage of your heart rate monitor, you need to know your TRUE MHR, which is only determined by physical tests run in a lab or on your own.

MHR is also activity-specific. For example, because one’s body weight is supported by his/her bike when cycling, MHR for biking is often lower than that for running. For best results, run physical tests to determine your MHR for different sports.

What is Resting Heart Rate (RHR)?

RHR is the heart rate of a person when he is completely at rest and not performing any activities. It is best measured at waking time. It is suggested that you take several readings of continuous mornings and use the average number as your RHR. This is because one might not get complete rest since quality of sleep is affected by stress or other factors.

Unlike MHR, RHR is affected by one’s fitness level. Your RHR drops when your fitness level elevates. People generally use their RHR to examine the quality of their workout program and make adjustments accordingly.

Target Zone Rates:

Two methods are used to calculate target zone heart rates: Standard Method and Karvonen Method.

The Standard Method:
The Standard Method takes the MHR and multiplies it by the percentage of one’s target zone to determine the target zone rates:

For example, if your MHR is 196:

The Karvonen Method:

The Karvonen Method is widely adopted in the world of endurance sports. The calculation of the Karvonen Method involves both MHR and RHR. Considering one’s RHR changes along with one’s fitness level, the Karvonen Method is believed to be more “realistic.”

The Karvonen Method multiplies the difference of MHR and RHR by intensity and adds RHR to the product.

For example, if your MHR is 196 and RHR 60:

Forthcoming articles:

How to measure your MHR on your own?
What do different zones mean and how do we incorporate them in a training program?

Picture: a Timex heart rate monitor