Design Your Cardio Around Frequency, Intensity, and Duration to Burn Fat

Your body has two basic ways of generating energy for your muscles in response to exercise.  One involves your body using oxygen to burn calories to provide fuel to exercising muscles.  In this method, your body is most efficient in burning stored body fat because fat must have oxygen present to be converted into energy to fuel your muscles.  Activities that cause your body to use this method to generate energy are called aerobic.  Examples are brisk walking and slow running.  When you are doing activities such as these, you are exercising in the aerobic zone.

The other method that your body provides fuel to muscles does not require the use of oxygen.  In this method your body primarily uses carbohydrates that are stored in the muscle to generate energy.  Activities that require a quick burst of energy such as heavy weight lifting and sprinting require your body to use this method.  Activities that cause your body to use this energy production system are called anaerobic exercises.

Knowing which energy system you are using when you exercise is important if you want to maximize fat burning.  In my fitness program, I do strength training in the anaerobic zone to build and maintain muscle; I do cardio in the aerobic zone to burn fat.

When planning your cardio exercise program design it around the following three concepts:

• Frequency – I recommend you do at least three sessions of cardio each week but no more than six.  This is ample exercise to achieve the health benefit, and burn body fat, while also giving your body maximum recovery time to build and maintain your hard earned muscle mass.  I personally do four to five cardio sessions per week as a part of my fitness program.

• Intensity – I suggest you do your cardio exercise in the range of 60 to 80 percent of your estimated maximum heart rate.  This is called your aerobic zone and is where your body is most efficient at burning fat as fuel.  Anything above 80 percent of your estimated maximum heart rate will tap into your anaerobic energy production system meaning you will stop using stored body fat to feed your muscles.

Use the following method to calculate your estimated maximum heart rate and your aerobic exercise zone.  Take the number 220 and subtract your age.  This is your estimated maximum heart rate.  Now take 60 percent of this number to get the lower end of the range of your aerobic zone and 80 percent of this number to get the upper end.

For example, I am 57 years old, so my estimated maximum heart rate is 220 – 57 = 163 beats per minute (bpm).  Therefore, the lower end of the range of my aerobic zone is 163 bpm x 60% = 98 bpm, and the upper end of my aerobic zone is 169 bpm x 80% = 130 bpm.  So when I do my cardio exercise, I work out at a heart rate between 98 to 130 bpm.

The easiest the way to see if you are staying in your aerobic zone is with a heart rate monitor.  If you do not have access to a heart rate monitor, you can use the following method to check your heart rate and stay in your aerobic zone.  Take the lower and upper range numbers you calculated above and divide them by four.  This is your 15 second heart rate count.  Then during your work out periodically stop and check your pulse for 15 seconds to see if your heart rate falls between the two numbers you just calculated.

I’ll use my example again.  The lower and upper ends of the range of my aerobic zone is 98 and 130 bpm, respectively.  Therefore, my 15 second heart rate count is 98 bpm / 4 = 25 for the lower end of the range and 130 / 4 = 33 for the upper end.  Thus, when I’m doing cardio, I stop to check my pulse for 15 seconds making sure the number I get is between 25 and 33, so I’m in my aerobic exercise zone.  This is the intensity range that my body is most efficient at burning fat for fuel to provide my muscles the energy to exercise.

Duration – It is my observation that you get the most benefit from your cardio program if you combine it with strength training and do between 30 and 45 minutes three to six days each week.  Do the 30 minute sessions after strength training and the 45 minute sessions on the days that you do not weight lift.

Design your cardio exercise program around the three principles above and you’ll notice a real difference in the way you look and feel.

A strength training program combined with regular cardio is the most effective way of maintaining your health and fitness level.  You can download my strength training programs by clicking on this link: Forever Fit and Firm.