The Fat Burning Zone

If your read the previous blog you will know how to determine your maximum heart rate so now we need to put it to some use. The most common training zone is often called the fat burning zone and is around 70-75% of your hr max. This zone is where your body burns the largest amount of calories from fat. It is not the zone that burns the most calories however. Many people think that because a relatively large amount of fat is burnt this is all they have to do. Unfortunately it is a bit more complicated than that. A brief explanation is required to show what I mean.

Fat takes more time to process as an energy source than carbohydrates so can only be used at lower intensities of exercise. As the intensity increases the fat burning process cant keep up with the bodies need for energy so it obtains more and more of its energy from carbohydrates until it is almost solely carbohydrates being used. At very low intensities most of the energy being used us from fat but because it is low intensity not much energy is required. The 70-75% figure is the point where the greatest amount of calories is being derived from fat, above this level fat usage decreases and carbohydrate usage increases. This figure is not a hard and fast rule but is a good guideline to go by.

So if the 70-75% zone is the best for fat burning why don’t we do all our training there? Well there are a couple of problems. First of all it usually takes 10-20 minutes for the body to effectively get the fat burning system up and running so if you only do 15-20 minutes then you will not be getting the most out of this kind of training. The second problem is although this zone burns the greatest amount of calories from fat it doesn’t actually burn that many calories so to make it really effective you need to do it for a prolonged period of time, 2-3 hours is ideal. Not every either wants to or has the time to do this however. Having said that it is still the best training zone to get you back into exercise. Start of with 15 minutes or so and once you can do 45 minutes or more non stop you will be ready to step your training up.

The next blog will discuss the best way to improve fitness. Make sure you have a read.