Getting Your Heart Rate Up vs. Burning Fat

I have had a lot of experience learning the different ways our bodies work, and just to clarify I DO realize that everyone’s body has a different metabolism and different needs, so take this with a grain of salt. However, I think this information is generally either misunderstood or just ignored because it requires calculation.

What is CARDIO???

“Some people refer to Cardiovascular exercise as aerobic exercise, some people even call it ‘cardio’ for short. All it amounts to is exercises that involve the large muscles like legs and help make your heart and lungs stronger. Cardiovascular exercise has lots of health benefits like lowering your blood pressure, and also it can burn lots of calories – for those of you who want to lose weight.

Cardiovascular exercise is activity involving the large muscles, such as your legs. The word ‘aerobic’ refers to something that needs oxygen. During cardiovascular or aerobic exercise oxygen gets continuously delivered to your muscles. Outside of exercise, terms like ‘aerobic bacteria’ refer to bacteria that need oxygen to survive, and ‘anaerobic bacteria’ are ones that do not need oxygen to stay alive.

To give your heart a proper workout you need to make sure that you do your “cardio” exercise with a certain amount of intensity, but you don’t want to overdo it. One way measure the amount of exertion while exercising is by monitoring your heart rate.

You can measure your heart rate manually or with a heart rate monitor. Heart rate is the number of times your heart beats per minute. Everyone has a resting heart rate, which is just what it sounds like – the rate your heart beats per minute while you are resting. Everyone also has a maximum heart rate, which the maximum amount of times your heart can beat in a minute. Your ‘target heart rate zone’ is a range of heart rate that is considered to be the best rate to be in to give your heart a good workout. This range is between 50% and 85% of your maximum heart rate.

Your maximum heart rate can be determined by a doctor, or you can use a formula to calculate a rough estimate. The most common way to calculate it is the following:

For women:
226 – (your age) = your maximum heart rate

For men:
220 – (your age) = your maximum heart rate

For example, if you are a 32 year old woman: subtract 32 from 226

226 – 32 = 194

Then take that number and multiply it by .5, to get your lower end of your target zone. And then multiply that same number by .85 to get the upper end of your zone. For example:

194 x .5 = 97
194 x .85 = 164.9

So, for a 32 year old woman an estimate of her maximum heart rate is 194. And her ‘target heart rate zone’ is between 97 and 164.9 heart beats per minute.”

MY POINT: If you are exercising BEYOND your heart rate zone, it is too hard on your heart and you will burn sugars instead of fat cells because your heart cannot push enough blood to your muscles to utilize the fat. Yes, you are burning calories, but as far as getting that fat off your body, NOPE. You are just fatiguing your body and muscles by burning all your simple sugars that your body uses during your regular resting heart rate, leaving you with nothing- and your body knows it and guess what? The calories you eat during the next 12 hours will be stored as FAT cells because your body feels depleted.

So the bottom line is be careful to stay in your target heart zone or you will not lose FAT cells and may possibly even gain a few!

HERE IS AN EXAMPLE of how to LOSE WEIGHT and burn the right calories:

The body does burn a higher percentage of calories from fat in the fat burning zone or at lower intensities. However, at higher intensities (70-90% of your maximum heart rate), you burn a greater number of overall calories, which is what matters when it comes to losing weight. The chart below details the fat calories expended by a 130-pound woman during cardio exercise:

Low Intensity – 60-65% MHR High Intensity – 80-85% MHR
Total Calories expended per min. 4.86 6.86
Fat Calories expended per min. 2.43 2.7
Total Calories expended in 30 min. 146 206
Total Fat calories expended in 30 min. 73 82
Percentage of fat calories burned 50% 39.85%

Source: From The 24/5 Complete Personal Training Manual, 24 Hour Fitness, 2000

In this example, the woman burns more total calories and more fat calories at a higher intensity. This isn’t to say that low intensity exercise doesn’t have it’s place. In fact, endurance workouts should be a staple of a complete fitness program along with shorter, higher intensity workouts or interval workouts (like Circuit [Curves]), which are a great way to burn calories and build endurance.