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Question: What is your TARGET HEART ZONE (THZ) and why is it important?

Answer: Your TARGET HEART ZONE is the number of times per minute your heart should beat during exercise. This is important for 2 reasons. First, it is how you can force your body to burn fat for energy. Second, it is where you will receive the maximum benefit for your cardiovascular system. Although most people work out to look better, you should also want to be healthier. By keeping your heart rate in this zone during exercise, you can accomplish both. If you stay within this zone for a minimum of 20-30 minutes 3 to 5 times a week you will receive the maximal benefit for your heart and lungs. If you want to lose body fat you should increase the amount of time and days per week.

Use the following formulas to find your THZ or Training Heart Rate Range (THRR)

The simplest way is the age predicted formula. Begin by subtracting your age from 220 to get your Maximal Heart Rate (MHR). This is the theoretical maximum number of times your heart could beat per minute at your age. You should not exercise at this level because it is very stressful and fatiguing to the body.

Multiply your MHR number by 55% and 85% to find your target heart zone. This is the formula you will see on posters on the walls of aerobic rooms.

I don't usually use this because it doesn't take into account the individual level of fitness for each person. For example, a 60 year old who is sedentary would not want to work out at the same level as a 60 year old that works out regularly. To factor in this difference I prefer to use the Karvonen Formula that is more specific to the individual's level of fitness.

Start by determining your Resting Heart Rate (RHR)-this is how many times your heart beats each minute. To be accurate, you should do this first thing in the morning upon waking. Find your pulse at your radial artery on the on your wrist and count how many times your heart beats in 60 seconds.

Then use this step-by-step method of finding your THZ by using the Karvonen Formula.

1.        Determine Maximum Heart Rate (220-age)

2.        Subtract Resting Heart Rate from that number. This is your Heart Rate Reserve (HRR)

3.        Multiply HRR (step 2) by 55% and 85%.

4.        Add your Resting Heart Rate back to the answers of step 3.

The resulting range is your THZ or THRR. The lower number represents the range that is generally recommended for beginners, heavy smokers, or those recovering from illness. The upper number would be used for highly trained competitive athletes or those who are at a high level of fitness. It could be very dangerous for untrained people to work at the higher end of their THZ.