The Ugly Truth

ProTFitness

The Ugly Truth

The body does burn a higher percentage of calories from fat in the 'fat burning zone' or at lower intensities. But, at higher intensities, you burn a greater number of overall calories which is what you should be concerned about when trying to lose 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%

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 even interval workouts which are a great way to burn calories and build endurance. To figure out your own intensity levels, start by calculating your target heart rate zone.

What is Your Target Heart Rate?

In order to figure out which zone you're in, you first need to figure out what your own target heart rate is. You can do this by using the Karvonen Formula. You can also use any number of target heart rate calculators to get your heart rate zone, but many of them do not incorporate your resting heart rate (which makes it a bit more accurate).

Below is an example of the Karvonen formula for a 23 year old person with a resting heart rate of 65 beats per minute (*to get your resting heart rate, take your pulse for one full minute.):

220 - 23 (age) = 197
197 - 65 (resting heart rate) = 132
132 * 65% (low end of heart rate) OR 85% (high end) = 85.8 OR 112.2
85.8 + 65 (resting heart rate) = 150 112.2 + 65 (rhr) = 177
The target heart rate zone for this person would be 150 to 177

For this person to work in his 'fat burning' zone, he would need to stay around 150 beats per minute or lower. To work within his 'cardio' zone, he would need to work at 150 bpm or higher. This step-by-step article will help you learn more about finding your target heart rate and how to use it.

cardbucfan

Where can I find the article? This is exactly the information I was asking about this weekend. Thanks!

SaraTN

Some important things to consider regarding Cardio:

1) low intensity steady state (LISS) - this is probably what most people are familiar with, cardio that gets your heart rate (HR) at about 65% of its max value for 45 minutes. This puts your body in a fat burning state without risking muscle. I've also heard people use this term to refer to walking as well. You can't get your heart-rate up as high, but you still can burn fat. low intensity workouts. These are workouts where your heart is 60-70% max value, and you do it for roughly 45 minutes. Walking pretty fast at a high incline is also good. Running, elliptical, rowing, bicycle, stepper, all of these are good.

2) high intensity interval training (HIIT). this is a little more advanced, please search around for more info before doing this. It involves alternating between pushing yourself extremely hard (higher than 75% of the max HR) for a length of time (like a minute) and then slowing down and recovering for the next minute. The principle is, that by alternating like this, your body actually thinks you are exerting yourself at the high intensity for the entire time. So you can get the same workout in less time. HIIT workouts are more typically 20-30 minutes.

Many people recommend LISS on an empty stomach first thing in the morning. Some people recommend this for HIIT as well although this seems a riskier way to lose fat as you may lose muscle as well. By doing cardio on an empty stomach, you force your body to draw on fat storage instead of food in your system. Of course if you can't do cardio in the morning. Do it whenever you like. I don't think the effect of doing it in the morning is that big and you will still have a great benefit to your health doing cardio.

I've seen lots of people say that you should not eat anything for up to an hour after performing cardio. The fat burning process can continue that whole time. Although as soon as you eat something, it stops. You can and should definitely drink water. This will never stop fat loss. Water is necessary and should be consumed all day long.

First and foremost, do it.

ProTFitness

ask.com exercise

buffalogal1979

Here is another article that gives similar info - specifically with regards to running.
Interesting stuff.
http://www.runningplanet.com/training/running-intensity-weight-loss.html

Lindsay7360

Interesting thread, thanks!

GiGi76

Bump