How exactly does exercise burn fat, in the human body?

By Raymond Onyango.

 Weight loss is big business, and every year individuals from all walks of life spend billions of shillings joining health clubs and seeking our all manner of pills, concoctions and diets that will do the trick in the shortest time. Needless to say, most of them fail in their quest, quite often not for want of sufficient effort but rather for lack of a proper understanding of how what cause a human being to lose weight. This will constitute our topic of discussion this week!

Basal Metabolic Rate

There are two things that directly influence your ability to lose weight, and these are your basal metabolic rate or the amount of calories your body needs to maintain itself; and of course the amount of energy we out our in work or exercise or even mental thought. It is generally accepted within the fitness community that the average human body needs at least 2200 calories a day, just power its every day activities – this is the basal metabolic rate. Weight loss happens when you take in less than 2200 calories in food a day or otherwise engage in exercise or movement which expends more calories than the amount you take in though food.

Fairly straightforward isn’t it? Well not quite. You could go on a diet like many people do but even that wont help you lose weight very quickly. The human body is incredibly resilient in the face of starvation. Lets do the math; we have established that the average human being has a basal metabolic rate of 2200 calories a day.  What I did not tell you yet is that each kilogram of stored body fat contains at least 7700 calories in it.  At this rate the human body looses about 1 kilogram of body fat every 3.5 days of total starvation. You would have to commit yourself to a month without food to lose just 10 kilograms of excess body weight! Not very much indeed!

Why Starvation Diets Don’t Work

Okay, so the starvation diet will not work, how about exercise? Running on the treadmill everyday should get you there quick, shouldn’t it! Well, only if you know what you are doing. Let us start by understanding a very basic principle of energy – it cannot be destroyed only converted. The petrol energy you put into your car’s fuel tank is converted into fire a series of controlled explosions in the engine which turns a crankshaft, which turns the wheels, and gets the car moving.  Your body is much like a car, and body fat believe it or not, has roughly the same amount of stored energy in it and a litter of petrol – which is why it is such an excellent source of emergency energy.  To loose the fat, you must use up the energy stored in it, but doing somehow, it cannot just melt away!

Factors That Influence Weight Loss

There are 3 things that will influence you ability to lose weight through exercise, these include your workload, your rate of breathing (VO2 Max) and your body temperature during exercise. Let us start out with the workload.  Workload is the trigger that sets off the chain reaction that causes your body to use up the energy it has stored as body fat. This is how it happens.

When you begin to run on the treadmill your muscles demand more energy to meet measure up to the demand. To deliver this energy, your body must process it more quickly by synthesizing stored body fat or blood sugar into the mechanical energy needed to move you.

This increased rate of metabolism requires more oxygen to fuel it and remove it’s by products including carbon dioxide. Your body responds to this by increasing your rate of breathing from an average of 12 to 18 breaths to a much faster rate depending on the intensity at which you are working.

How Getting Hot And Breathless Helps You Loose  Weight

The increased rate of breathing and metabolism produces heat, which if allowed to accumulate would cause the body to overheat and must thus be lust though sweat and water vapor in the lungs. It is estimated that the human body works at about 20 percent thermal efficiency, meaning that for every 100 calories you consume, only about 20 of them are converted into actual work, the other 80 are lost to metabolic processes and the heat that they produce, which is why cardiovascular exercises that make you sweat are integral to your weight loss efforts.

Next week we will examine these three factors that influence your capacity to lose weight in greater depth, but at this moment I will conclude saying that you can only really lose weight by increasing your rate of breathing and your body temperature. People selling you products that claim to melt away your body fat are simply selling you lies. That fat energy as we have seen cannot be destroyed or melted away, it has to go somewhere – and that will be the topic of our discussion next week!

Have an active week will you!

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