Why You Should Avoid Exercise (4 page)

Once you have eaten and fully replenished the glycogen that was drained from the muscles and liver, the body will switch out of the fight-or-flight response because it will 'think' the danger is over. But switching out of the fight-or-flight response is not quick; it can typically take a day or so providing you cease exercising. If you exercise everyday you stay in a semi-permanent state of 'fight-or-flight' as you don't give the body a chance to fully switch out of survival mode - this is very bad for health in many ways.

Furthermore, as a result of exercise you will tend to over-eat to replace lost glycogen. But in doing so the body will store any excess glucose as surplus body-fat.

Do not underestimate the previous statement. When blood glucose is too low (known as hypoglycaemia) you risk a medical emergency such as feinting or falling into a coma. Hence, when exercise drains the muscles of glycogen, you are compelled to consume food/drink to give the body a quick source of glucose for replenishing the lost glycogen. We all know the feeling of urgent hunger and weakness from a lack of energy after a bout of exercise or strenuous activity.

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If your liver and muscles are already full of glycogen, and can't accept any more, the body then converts the excess glucose to fat and stores it in your fat cells. This process is called lipogenesis
". Source: Dr. Jeff Volek and Dr. Steve Phinney, www.ketogenic-diet-resource.com.

You may not feel hungry the moment you finish exercising, but you can be sure that at some point later on during the day or evening you will need to eat to replace the lost energy. And when you do eventually eat, the body will be primed to store as much of that food-energy as body-fat once the muscles have been replenished with glycogen.

3. Exercise and the Cortisol Factor

Exercise significantly increases the level of cortisol in the blood as a result of the physical stress imposed on the body. Even at mild or moderates levels of exercise, it is known that this increases the amount of cortisol in the bloodstream, and this in turn increases obesity:

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Sustained exercise, even in a thermally comfortable environment, induces a larger hormonal response than moderate thermal stress. With moderate exercise, increases in leukocyte numbers are related mainly to plasma norepinephrine concentrations, but with more intense exercise epinephrine concentrations assume a major importance. As exercise continues, plasma Cortisol levels also rise.
" Source: I. Brenner, et al, Stress Hormones and the Immunological Responses to Heat and Exercise, J Sports Med 1998; 19(2): 130-143.

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Collectively, the cortisol findings support the view that moderate to high intensity exercise provokes increases in circulating cortisol levels
." Source: Hill EE, et al, Exercise and circulating cortisol levels: the intensity threshold effect, J Endocrinol Invest. 2008 Jul; 31(7):587-91.

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Cortisol affects fat distribution by causing fat to be stored centrally—around the organs. Cortisol exposure can increase visceral fat—the fat surrounding the organs—in animals
." Source: Elissa Epel, et al, Stress May Cause Excess Abdominal Fat In Otherwise Slender Women, Psychosomatic Medicine, Sept. 2012.

When cortisol in the blood rises, this has the direct effect of increasing body-fat. This is why athletes and those who exercise regularly are much more prone to being overweight. It is ironic that most people who go running do so to be slim, yet that same exercise only serves to make them fatter.

Worse still is the fact that the surplus body-fat gained from exercise is of the worst kind. The higher levels of cortisol gained from exercise pre-dispose the body to store fat around the midriff. In women this means around the waist, hips, thighs and buttocks. In men it means around the abdomen, giving men a pot belly or ‘spare tire’. This type of surplus body-fat is particularly unhealthy and very difficult to get rid of.

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One of the interesting but ‘paradoxical’ observations in my clinical practice is the rather large number of patients presenting with severe obesity, who have histories of successful competitive sports careers.
" Source: - Dr. Arya Sharma, MD/PhD, FRCPC, Prof. of Medicine & Chair in Obesity Research and Management at the University of Alberta, Canada, www.drsharma.ca.

Cortisol in the blood goes up as a result of the 'fight-or-flight' response and is well documented in medical literature. The fight-or-flight response is described as an acute stress response in which the body is prepared to face some kind of emergency. When you are faced with danger or panic for example, the body is put into a state of fight-or-flight (a kind of automatic survival mechanism).

So when the body thinks that you are facing danger (from the stress of exercise), many hormones are galvanized to get the body ready for emergency action. Cortisol makes blood glucose go up to give you maximum energy,

"
If your liver and muscles are already full of glycogen, and can't accept any more, the body then converts the excess glucose to fat and stores it in your fat cells. This process is called lipogenesis
". Source: Dr. Jeff Volek and Dr. Steve Phinney, www.ketogenic-diet-resource.com.

But cortisol is not your enemy; it fulfils several vital functions and is used by the body as a survival mechanism when faced with danger. Your enemy is the exercise that stresses the body - this is what triggers cortisol. Equally, glucose is not your enemy (in the context of body weight); your enemy is surplus body-fat.

The body is compelled to keep blood glucose within a very narrow range: just enough for keeping you alive, energized and healthy. Too little or too much glucose in the blood can lead to serious illness or an emergency medical condition.

Hence, when cortisol pushes up the level of glucose in the blood it is a very temporary condition to get you out of trouble. Then soon afterwards the body uses insulin to bring down the level of glucose. This is when surplus glucose is stored as body-fat.

To summarize: exercise pushes up blood cortisol and blood glucose. After the exercise, insulin brings down the level of glucose in the blood by storing excess glucose as body-fat around the hips, thighs, buttocks and stomach. Hence, cortisol has a direct effect on increasing the body's propensity to store surplus body-fat.

4. Exercise and the Leptin Factor

Exercise reduces the level of leptin in the blood, and this causes hunger, over-eating, food cravings and junk-food consumption.

Leptin is a powerful hormone produced by the body to control feelings of hunger. It is always circulating in the blood and its role is to keep body weight within a healthy narrow range. If your body-fat falls below the norm (the 'baseline level') leptin levels in the blood will go down to make you eat more by increasing feelings of hunger. If your body-fat goes above the norm, leptin levels in the blood will go up to make you eat less by reducing feelings of hunger.

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Leptin circulates in blood and acts on the hypothalamus to regulate food intake and energy expenditure. When fat mass falls, plasma leptin levels fall stimulating appetite and suppressing energy expenditure until fat mass is restored. When fat mass increases, leptin levels increase, suppressing appetite until weight is lost
". Source: Wikipedia.

So in general the lower the level of leptin in the blood the fatter you become. The higher the level, the thinner you become. For those wishing to lose weight, leptin is truly the most important hormone to know about.

You may wonder how this relates to exercise? We will get there in a moment, but consider this: leptin is much more sensitive to starvation than to overfeeding; leptin levels go down more when food intake decreases than when it increases. Several studies clearly show this to be the case, such as the following*:

* Chin-Chance C, et al, Twenty-four-hour leptin levels respond to cumulative short-term energy imbalance and predict subsequent intake, 2000, J. Clin. Endocrinol. Metab. 85 (8): 2685–2691.

* Keim N, et al, Relation between circulating leptin concentrations and appetite during a prolonged, moderate energy deficit in women', 1998, Am. J. Clin. Nutr. 68 (4): 794–801.

* Mars M, et al, Fasting leptin and appetite responses induced by a 4-day 65 percent-energy-restricted diet, 2006, International journal of obesity (Lond) 30 (1): 122–128.

As already mentioned a major cause of obesity is a lack of underlying nutrition. We must remember that the body considers malnutrition as much a threat as starvation. To put it crudely: famine makes you fat. Over-eating does not make you fat if you stick to nutritious food. But if you eat junk food this deprives your body of good nutrition, and this is perceived by the body as 'famine' so leptin goes down to increase feelings of hunger. This is why fat people who always consume junk food are always hungry. Western society, especially the United States, is full of people who are severely overweight but who are also suffering from extreme malnourishment.

Leptin is mostly made from body-fat (white adipose tissue). So the fatter you become the greater the amount of leptin produced by the body. And here's the crunch: obese people force the blood stream to have a constantly higher level of circulating leptin, and this causes 'leptin resistance'. This is a medical condition similar to insulin resistance. When you have leptin resistance, the body becomes less capable of changing the level of leptin in the blood. This is disastrous because it means the body cannot make the level of blood leptin go up or down as a way of keeping body weight within a narrow range (not too fat, not too thin).

Millions of over-weight people are caught in a vicious circle of over-eating: they over-eat because of hunger, but as they eat nutritionally poor food, they stimulate feelings of hunger (by making their leptin go down or by causing leptin resistance) which in turn makes them eat yet more food! This is a major cause of obesity throughout the world.

This brings to light a paradox that causes great confusion: most fat people have high amounts of leptin circulating in the blood. If high leptin makes you eat less (from less hunger), how is it that most fat people are usually hungry and over-eat?

The answer to this paradox is that obesity causes leptin resistance, and this in turn causes the body to NOT take notice of the continuously high level leptin circulating in the blood. As a result, the on-going high level of leptin does not reduce feelings of hunger. To be absolutely clear on this vital point: the body is not taking any notice of the high leptin - it is resisting from taking action to make you eat less, hence leptin resistance.