Cardio Training 

About Your Target Heart Rate Training Zone
by Michael J. Merlino, BBA, ACE, BSMI (CPFT, RES,SCS), CIAR
Owner, Merlino Fitness, MerlinoFitness.com

Simply put, cardiovascular fitness is continually moving your large muscles like the legs to increase heart rate and burn sugar and eventually fat as an energy source to keep you moving.

When doing cardiovascular exercise it is important to train aerobically (using oxygen) to burn calories and fat stores efficiently. Your target heart rate training zone is an estimate of where your heart rate should be to insure that you are training aerobically. Training below your target zone may not be intense enough to burn enough calories and training above your zone will force your body to burn calories anaerobically (without or lacking oxygen) and inefficiently. Calculating your target zone below is only a beginning estimate of your target-training zone using the Karvonen formula. This formula assumes that at birth a newborn’s heart is capable of a maximum heart rate of 220 beats per minute and with each year the maximum heart rate decreases by one beat per minute as you age. It has an accuracy rate of + or - 10-12 beats per minute and may not be as accurate for those over 65 who may have significantly higher heart rates. Most people should be exercising in a zone that is 60 to 80% of their predicted maximum heart rate. The percentage may be adjusted slightly below the low end for those that are very sedentary or just starting an exercise program and slightly above the high end for athletes doing intense aerobic training. Always consult with a physician before starting a new exercise program.

To estimate your exercise heart rate to gauge whether you are in your target zone, take your pulse at your wrist while you are exercising for 10 seconds and multiply by 6. Another way to gauge your aerobic and anaerobic threshold is by using the talk test. If you are winded to the point where you cannot carry a conversation, chances are you are beyond the high end of your training zone and are training anaerobically. If this is the case slow up the pace until you catch your breath and return to your zone.

CALCULATING YOUR TARGET HEART RATE TRAINING ZONE USING THE KARVONEN FORMULA

Let’s take a look at this simple formula using Jane B. Fitt:

Step 1: Jane will need the following stats to begin

• Age – 38
• Resting heart rate (RHR) – Jane did this by taking her pulse and counting the beats per minute for one full minute as soon as she rose out of bed one morning. The average resting heart rate for men is 70 beats per minute while women have an average of 75 beats per minute.

Step 2: Calculate age predicted Maximum heart rate (MHR)

• 220 – age = predicted max heart rate(MHR)
  220 – 38 = 182

Step 3: Calculate resting heart rate (RHR)

• True resting heart rate is taken for 1 full minute as soon as you rise out of bed. Jane’s resting heart rate is about average at 72.

Step 4: Subtract resting heart rate from maximum heart rate to get heart rate reserve (HRR)

• MHR – RHR = HRR
  182 – 72 = 110

Step 5: Multiply HRR by 60 – 80% of your maximum heart rate which will set your upper and lower range limits:

• Multiply your heart rate reserve (HHR) by 60% and 80% and add your resting heart rate back in:
• Low end of range is HRR X .60
  110 X .60 = 66 + 72 (RHR) = 138
• High end of range is HRR X .80
  110 X .80 = 88 + 72 (RHR) = 160

RESULT: Jane’s beginning target heart rate training zone is:

138 ----------------------> 160

Keep in mind that your target heart rate training zone should only be used as a guideline. Let your body and your energy level dictate your intensity level during your cardio sessions.

Michael Merlino is a Certified Professional Fitness Trainer and owner of Merlino Fitness and MerlinoFitness.com. He trains his clients at the Houston Downtown YMCA and his private fitness studio. Michael can be reached at 713.523.2577 or e-mail him at michael@merlinofitness.com. Click on one of the links below for more information on Michael and his fitness services.

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