“If you want to lose a few kilograms, you need to do long, slow, steady-state aerobic exercise in the fat burning zone.”
Heard this advice before? It’s one of the biggest misconceptions in the exercise and weight-loss world. The argument is that low-intensity aerobic training will allow your body to use more fat as an energy source, thereby accelerating the loss of body fat. While it is true that a higher proportion of calories burned during low-intensity exercise come from fat (about 60 percent as opposed to approximately 35 percent from high-intensity programs), high-intensity exercise still burns more calories from fat in the final analysis. To illustrate this point better, I will show you a chart below.
As we can see from this chart, low intensity actually utilizes more fat! But the fat burning zone is nowhere near 20% of exercise intensity. The fat burning zone is between 55% to 65% of max.Therefore, there is another chart which I would like to show you. How much fat are you actually burning from the fat burning zone?
Wow, thats a whopping 37g of fat burnt in an hour. However in weight loss as we have discussed in the previous post titled “Nutrition”, the total calories expended would be more important to weight loss as it can help to create a negative enerygy balance. Although the fat burning zone burns a higher percentage of fat of the total calories expended, it does not burn more calories than training in high intensity. You may ask, but I would be burning 80% of carbohydrates and only 20% of fat, so how do I lose the fats then?
My recommendation to you would be to take on High Intensity Interval Training (HIIT).
A HIIT session consists of a warm up period of exercise, followed by six to ten repetitions of high intensity exercise, separated by medium intensity exercise, and ending with a period of cool down exercise. The high intensity exercise should be done at near maximum intensity. The medium exercise should be about 50% intensity. The number of repetitions and length of each depends on the exercise. The goal is to do at least six cycles, and to have the entire HIIT session last at least fifteen minutes and not more than twenty. HIIT is considered to be an excellent way to maximize a workout that is limited on time.
For example: I would start by doing a light jog at 40% to 50% intensity for 5 minutes first. After which, I would begin my HIIT with 30 seconds at 80% to 90% max, followed by 45 seconds recovery at about 50% max. This would be one repetition. Do vary the high intensity and recovery periods according to your fitness level (Principle of Individuality). Lastly, I would end the training session with another 3 to 5 minutes of light jogging at 40% max and finish with brisk walking to allow my heart rate to return to normal. I would then do static stretcing of the whole body and have a light post-workout snack to replenish my glycogen stores, electrolytes and hydration level.
How exactly does HIIT help in fat burning? Let me show you an example:
If you perform 30 minutes of low-intensity aerobic exercise (i.e., at a level of 50 percent of maximal exercise capacity), you’ll burn approximately 200 calories. About 120 of those, or 60 percent, come from fat. However, exercising for the same amount of time at a high intensity (i.e., 75 percent of your maximal exercise capacity) will burn approximately 400 calories, and 35 percent of them, or 140 calories, will come from stored fat. So by sticking to the fat-burning zone for their workouts, many individuals are wasting valuable time. Keep in mind that you lose weight and body fat when you expend more calories than you consume, not because you burn fat (or anything else) when you exercise. The bonus point is that even after exercise, your metabolism would be much higher, resulting in you burning extra calories for hours after your workout. That’s right, you’re burning more calories doing nothing!
Of course, the less intense form of exercise has its benefits as well. For example, because many overweight people tend to find that lower-intensity exercise is more comfortable, they may, therefore, be willing to engage in such workouts. The point to remember is that low-intensity workouts do, in fact, promote weight and fat loss. You just have to do them for a longer period of time.
To conclude, High Intensity Interval Training is more efficient in terms of time invested and total calories expended as compared to the fat burning zone. Do note that since the HIIT can be quite intense, it can lead to burnout from overtraining. Therefore, it is not advisable to do this everyday (probably on alternate days or when you feel that your body has adequately recovered. I have to emphasize this point greatly: High intensity exericse cannot be prescribed for individuals at risk for health problems and obese people who are not used to exericse.
Disclaimer: Please consult your physician or health professional before you begin any exercise, nutrition, or supplementation program or you have questions about your health. The author assumes no responsibility whatsoever for the consequences of your actions, whether direct or indirect.