Whenever we talk about losing weight or fat-burning metabolic rate is mentioned, in addition to referring to things like speed up metabolism and increase energy expenditure.
For those who do not at all clear that we see in detail is the basal metabolism.
Basal metabolism is the energy consumed in mechanical activities supporting life processes such as breathing, blood circulation, the synthesis of organic constituents, body temperature maintenance, etc.. It is, therefore, the energy required for maintaining normal physiological functions and homeostatic, with the body at rest and fasting.
Proportionally the energy used in basal metabolism is bound by 50% to cellular metabolism, 40% used for the synthesis of molecules, especially proteins, and 10% of the internal mechanical work, movement of respiratory muscles contraction of the heart, intestinal peristalsis, etc..
The metabolic cost depends on various factors: body temperature, ambient temperature, glandular activity, physical activity level, age, sex and feeding habits of each person.
Body temperature: each increase of 0.5 º C internal body temperature increases metabolic rate by 7% due to the temperature accelerates the chemical reactions that occur.
Thus, a patient with a temperature of 41 degrees C (about 4 º C above normal) show an increase of 30% of its metabolism.
Outside temperature: ambient temperature also affects the basal metabolism. Exposure to cold increases your caloric intake by the need to develop an extra heat to maintain body temperature.
A short exposure to high temperature has little effect on basal metabolism, but if exposure is of long duration also increases metabolism. It is estimated that in the tropics (average temperatures over 25 degrees) the basal metabolic rate decreases by 10%.
Glandular activity: the thyroid gland produces the hormone thyroxine which plays a key role in the metabolic activity of the body. The greater the production of thyroxine, the higher basal elmetabolismo so in thyrotoxicosis (a disease of the thyroid gland where the hormone thyroxine production is increased), basal elmetabolismo can bend.
Conversely, if the production of thyroxine is below normal, metabolism may be reduced to 30-40% of normal (this condition is called myxedema). Epinephrine also increases basal but elmetabolismo lesser extent than thyroxine.
Exercise: physical exercise is not only useful for burning calories, it also raises the metabolic rate to be more demanding muscle tissue than fat energy.
Thus, an individual muscle burns more calories while sleeping than a fat subject to the same height and weight.
Age: Children have very high metabolic rates (higher ratio of surface to body mass), whereas the elderly are lower.
Sex: is somewhat lower in women than in men because the natural ratio of body fat is higher.
Food: If we submit to a diet deficient in calories or prolonged fasting, the body dramatically lowers the energy consumed at rest to last longer available energy reserves.
As estimated basal metabolism
The basal metabolic rate is obtained by measuring the energy consumption during complete rest, measured in calories.
In practice, the basal metabolism is calculated by some equations that take into account, besides the weight, height and age. The most used is the Harris-Benedict equation:
For men
basal metabolic rate (cal) = 66.5 + (13.75 x weight in kg) + (5,003 x Height in cm) – (6,775 x age in years)
For women
basal metabolic rate (cal) = 655.1 + (9,563 x weight in kg) + (1,850 x height in cm) – (4,676 x age in years)
Tags: basal metabolism, burning calories, fat-burning metabolic rate, losing weight, metabolic, Metabolism,