Kenneth MacLeod, Director of the Clinical Research Laboratory at the University of Binghamton (New York), explains how heart function and metabolic rate are related, why diet and training are unlikely to help maintain lost weight and what does the sole muscles (part of the calf muscle).
- Everyone who has tried to lose weight and maintain the result knows how difficult it is. It seems that it’s easy - to reduce the daily calorie intake and exercise to burn them. But many
have shown that this obvious, at first glance, strategy is not very effective for most people.
How difficult it is to maintain weight can be found in a study by the National Institute of Health.
Scientists watched 14 participants in the reality show The Biggest Loser. Within 30 weeks - the show lasted so long - each of them threw an average of 55 kilograms. But six months after the end of the project, all participants except one scored about most of the lost weight, even though they continued to train and follow a diet.
Photo: shutterstock. com
Weight loss often leads to a slowdown in metabolism - it becomes difficult to maintain a new weight.
Why is this happening and is there a way to maintain a normal metabolic rate after losing weight?
A person has a soleus muscle - it helps circulate blood and other fluids in the body. It is important that this muscle always remains active - this will help maintain the metabolic rate when a person is sitting or standing. Function of the soleus muscle is the main subject of research at the Binghamton University Clinical Research Center. It is no coincidence that it is called the second heart - this muscle drives blood to the heart and thus allows you to maintain a normal metabolic rate at rest.
The main metabolism at rest (basal metabolism, Resting Metabolic Rate) is one of the biochemical processes that occur in the body when a person is physically inactive . This helps maintain breathing and, most importantly, maintain warmth.
A sitting position at room temperature is the standard RMR control point, it is considered one metabolic equivalent, or MET. A slow walk is about two METs, cycling - four METs, jogging - seven METs. As a rule, people do not need to move a lot in order to perform daily routine tasks, so for most people 80% of the calories spent per day are associated with the work of metabolism at rest.
When a person loses weight due to fat mass, the metabolic rate decreases slightly. But another thing is surprising: RMR slows down quite seriously in those people who lose weight through diet and exercise. Thus, the metabolic rate of participants in the show The Biggest Loser decreased by almost a third - 80% of their lost weight was just fat. A simple calculation shows: to compensate for such a large drop in metabolic rate, it takes almost two hours of daily brisk walking - in addition to normal daily activities. Most people cannot fit so much physical activity into their lifestyle.
There is no doubt that a balanced diet and regular exercise are beneficial, but accelerating RMR is a more effective strategy for losing weight and maintaining weight.
Photo: shutterstock. com
The metabolic rate depends on the delivery of oxygen to the tissues of the body. This occurs through the bloodstream, so cardiac output (the amount of blood that the heart pumps in a minute. - Approx.
Ed. ) is considered the main indicator of metabolic activity. The adult's body contains about four to five liters of blood, and all this blood must constantly circulate throughout the body. However, the amount of blood that the heart can pump out with each stroke depends on how much blood returns between these strokes.
If the veins were iron pipes, and the skin of the legs was stiff, like in birds, the cardiac outflow would always be equal to the cardiac inflow, but in a person everything happens differently.
The veins are quite flexible and can multiply in size, and soft skin can reduce body volume.
When a person sits, blood and interstitial fluid (the fluid that surrounds all the cells of the body. - Approx. Ed. ) accumulate in the lower parts of the body.
This reduces the amount of fluid returning to the heart, and accordingly reduces the amount of fluid that the heart can pump out during each contraction. Cardiac output decreases - and RMR decreases.
Our studies have shown that in middle-aged women, cardiac output in a sitting position decreases by about 20%. In people who have recently lost weight, the skin is much weaker and gives more space for the accumulation of fluids, because it has not yet had time to contract.
In young healthy people, fluids cannot accumulate indefinitely while they are sitting - the soleus muscle pumps blood and extracellular fluid back to the heart. That is why this muscle is called the second heart. However, with a sedentary lifestyle, this "heart" weakens, as a result, too much fluid collects in the lower body.
Excessive fluid buildup can create a vicious cycle. It reduces metabolism, then the body begins to produce less heat - people with a slow metabolism often get cold hands and feet.
The metabolic rate is highly dependent on the temperature of the tissues, therefore, RMR naturally decreases. A drop in body temperature - even a degree (Fahrenheit) - can lead to a decrease in RMR of 7%.
There is an obvious but expensive way to overcome the accumulation of fluids after weight loss - cosmetic surgery to remove excess skin. A recent study confirmed that people who underwent body contouring after bandaging the stomach (a method of surgical treatment of obesity by applying a bandage to the upper stomach that helps to eat less. - Approx.
Ed. ) controlled better their weight than those who did not do such an operation.
Flounder // Photo: shutterstock. com
The best way to maintain RMR after weight loss is to train the soleus muscle. This muscle is postural, that is, it is deeply located, therefore, to include it in the work, long and not very intense loads are needed.
For example, tai chi gymnastics is perfect for this.
Over the past few years, researchers at Binghamton University’s clinical science and technology lab have been looking for a convenient way to train the soleus muscle. As a result, they created a device that, with the help of mechanical vibrations, activates receptors on the sole of the foot, which in turn causes the muscle to contract reflexively.
The study involved 54 women aged 18 to 65 years, and scientists found that 24 of them suffered from secondary heart failure, leading to excessive accumulation of fluids in the legs. Stimulation of the soleus muscle helped them cope with this problem.
The ability to prevent the accumulation of fluids will allow people to maintain cardiac output, and therefore, maintain an active metabolism - even at rest.
This material was first published here.