SPOT REDUCTION : Its physiological foundations
It is well known that when a person starts a diet, they lose fat more quickly in the areas where they are already thinner.
For instance, if a woman with small breasts who wants to lose weight because she has wide hips starts following a low-calorie diet, her breasts will reduce in size, whilst she will lose virtually nothing from the hips. In the same way, a man who starts a diet to build a “six-pack” will reduce his waistline, but his “love handles” and the fat that hides the abdominal muscle will tend to resist. This is due to the fact that most of the fat loss is affects the inter-abdominal visceral fat and not the subcutaneous fat that “covers” the muscles. If all the fat came from the subcutaneous zone, our six-pack would come out in a few weeks, and normally we try to obtain this result by increasing the work at the gym in that area of the body. As we have already said, there are no physiological explanations about how to burn subcutaneous fat adjacent to the muscle more directly by physical training. From the physiological standpoint, it is hard to understand how the muscle can use the adjacent fat, since it does not have “tentacles” that invade the fat; nor does it produce substances that destroy fat. Besides, how can training the muscle orientate lipolysis towards it?
The muscle’s energy comes from two sources: 1) from the glycogen and from the triglycerides stored in the muscle cells, that are then transformed into ATP; 2) from the blood, that supplies glucose from the diet and fatty acids deriving either from the diet or from lipolysis of the adipose tissue. The fat is normally stored in the form of triglycerides in the adipose cells.
To empty these adipocytes we need to induce a process called lipolysis. When we follow a low-calorie diet, we stimulate two different processes: 1) lipolysis of the adipose tissue, to make the fat, in the form of fatty acids, pass through the adipose cells into the blood; 2) the β-oxidation of fats, i.e. the process whereby fatty acids transported in the blood and captured by cells like muscle cells are burned to produce energy. If we managed to introduce lipolysis in a specific area, the spot reduction would be within our grasp.
The lipolysis is fundamentally stimulated by two hormones: adrenaline and noradrenaline, which act on two specific kinds of receptors: α-adrenergics and β-adrenergics receptors. The ones that are involved in the adipose tissue are the α-2-adrenergics and the β1, β2 and β3 adrenergics. The hormones adrenaline and noradrenaline circulate in the blood and carry out their effect, which can vary depending on the receptors they bind with. The adipose tissue has both alpha (α) and beta (β) receptors. When the hormones bind with the latter they stimulate lipolysis, but when they bind with the former they inhibit it.
In men, the adipose tissue in the abdominal region has a proportionally lower percentage of beta-adrenergic receptors and a higher percentage of alpha receptors, while in women there are more beta receptors in the abdominal area and alpha in the gluteus and thighs.
This distribution is influenced by the sex hormones: testosterone and estrogen. Hence, despite a higher concentration in the blood of adrenaline and noradrenaline produced by the adrenals during the low-calorie diet, and in spite of the fact that we can increase their local production and release directly from the nerve, since these substances work as neurotransmitters during muscle contraction, if we have a high concentration of α-2-receptors and a low concentration of β-receptors, the lipolytic effect will still be poor.
We can, in part, improve the situation using substances that directly stimulate the β- receptors (synephrine, caffeine) and others that inhibit the α-2 receptor (yohimbine), so that all the effects of the β-adrenergic substances will flow to the lipolytic β-receptors, but if they are lacking the effect will still be poor, hence we need to use another mechanism.
The fat contained in the adipocytes is not stable, but is instead in continuous renewal; we could say that it is completely renewed every three weeks and, in a normal-calorie diet, a lot of fat is melted and a lot is re-synthetized, i.e. a lot of fat leaves the adipose cell and a lot goes inside. This mechanism of renewal also occurs when we have a calorie deficit, only the incoming amount is lower than the outgoing amount.
If we were able to prevent fats from entering the adipose cells in specific areas, we would manage to achieve a better localized fat loss effect.
We have already seen that the most important factor in body fat distribution is the hormones: when hyper-insulinism occurs, the testosterone creates an accumulation in the waistline and the estrogen in the lower part of the body. Yet there is also another important factor. You will no doubt have noticed how even people who are actually overweight still tend to have a low percentage of fat in the forearm, and the same can be said for the calf muscles, unless they have circulation problems. Generally the forearms and the calf muscles are the leanest parts, and also the ones that are constantly moving; in these parts there is a constant muscular stimulation that increases the local bloodstream. In other words, give me a person that has circulation problems in the lower part of the body, calf muscles included, and I will show you a person with a fat accumulation in the lower part of the body, calf muscles included, that withstands every kind of diet. This scenario is often seen in women. There is a direct correlation between the amount of blood that reaches a specific area and the amount of fat in the same area. The higher the bloodstream, the lower the fat accumulation, and vice-versa. This is made possible by the fact that the bloodstream increase reduces the esterification of the fatty acids, which is the basis of the renewal process of the adipose tissue that carries the fatty acids inside the adipose cell.
Each time the bloodstream is reduced, new fatty acids can enter the adipose cell more easily. So if we could permanently increase the amount of blood in a specific area, it could unbalance the renewal of the fatty acids, reducing the normal replacement in the adipose cell.
To obtain this effect it is not enough to increase the bloodstream occasionally, even if the increase is consistent; we need to do it in an almost permanent way. Many people who try localized fat loss train those areas from three to six times per week with a remarkable amount of work. This is ok and undoubtedly increases circulation, but for a short period; it is better to attack the same area more times every day, if we want to see considerable localized fat loss, at least three times for a minimum of 15 minutes, to stimulate the bloodstream in that area in an almost permanent way.
The risk involved in this type of strategy is that it can result in overtraining due to an excessive amount of work and the high effort involved psychologically speaking. Moreover, muscles worked out so frequently can lack sufficient rest. This can result in catabolism, a condition that tends to prevent fat loss and a toned appearance in that part of the body. Consequently the best strategy for localized fat loss is a combination of actions that aim to improve the circulation in that area in both an active and passive way.
Accordingly the use of electro-stimulating devices, manual massages, hydro-massage and creams and supplements with a draining and healthy effect on the circulation (equisetum, birch, ginkgo biloba, flavonoids, niacin) are all useful. Localized cellulite, or panniculopathy, is actually caused by a microangiopathy with capillary-venous stasis, i.e. a disease affecting microcirculation, causing poor distribution of the blood flow. The problem becomes tough to solve when this pathology is at an advanced stage (fourth stage), when the calcification of the adipose tissue (liposclerosis) and the creation of connective “girders” with the formation of macronodules tends to exclude adipose tissue in the area of the bloodstream even more, with all the resultant consequences that we have already seen (the fats enter the adipose cells more easily), whilst limiting the entrance of lipolytic hormones.
So the fight against localized fat and cellulite is not lost from the start, especially if we start early, using all the “weapons” at our disposal.
* From the booklet “Corso per personal trainer” (Personal trainer course)- Accademia del Fitness, October 1997.
