EXERCISING TO SHED FAT?

Pic: Me jogging around my neighborhood.

I met a friend in her early 30's who tried to lose weight by going to the gym but without success. I asked what was she doing and she replied that she was doing 25 minutes of treadmill. I then asked her what heart rate was she achieving and she said 150 beats per min (This is far too high if she had wanted to burn fat).


You do not start to burn fat as soon as you begin your work out. The first 20 minutes of exercise the body burns sugar from the glycogen stores. The next 10 minutes it is a mixture of sugar and fats. Only after 30 minutes does the body burn predominately fat. The key about fat burning is to exercise not hard but long.

Studies show that to shed fat demands continuous movements of at least 30 minutes duration carried out at least 3 times a week. It has to be continuous and should you stop and restart workout after 20 minutes of exercise, the hormonal shift has reverted to burning sugar again. For beginners, you may find that your muscles may not sustain exercise for 30 minutes (aim for 45-60 mins). It is okay as it may take several weeks to build up your muscular strength first.

SLOW DOWN. Many so-called instructors advocate a training heart rate of 60-70 percent of the maximal heart rate (220 minus your age; ie. if you are age 30, your maximal heart rate is 190). However, at that kind of rate the unfit majority will reach their anaerobic threshold, and the body will burn mostly protein and sugar. That is why you see so many overweight women in aerobic classes and overweight men jogging in the park, panting like mad.

In fact, the optimal intensity of exercise for fat burning is far lower at 50-60 percent of your maximal heart rate. A daily walk of at least 30 minutes (longer the better, with no stops) will burn far more fat than killing yourself at the gym.

Body fat is very caloric dense. It needs a lot of oxygen to be metabolized – broken down – so that it can be put into the bloodstream and used as energy. If your workout is too intense (i.e. HEART RATE 150), the body will not be supplied with enough oxygen and switch to other tissue for energy. In effect it will stop burning your stored fat and increase its burning of protein and glucose, for these tissues require less oxygen to burn.