BMR? Is that just another useless three letter combination created by filthy companies who want us to feel that we are not good enough? (Like BMI is.)
In fact NO. BMR is actually a good tool to use in your attempt to build a good physic. If you just know its weak points. Cause there is weak points in BMR.
BMR stands for Basic Metabolic Rate. BMR is the amount of calories your body need in total rest for 24 hours. In rest, energy will be used only to maintain cell reproduction in vital organs, which includes the heart, lungs, kidneys, nervous system, intestines, liver, sex organs, muscles, and skin. All cells in your body are born, live its life and dies. That process needs energy. Nutrient processing, circulation and breathing needs energy. Life-supporting functions needs energy in total rest. That energy counted in calories per 24 hours is BMR.
You can calculate your BMR with the Harris & Benedict Equation or the Mifflin – St Jeor Equation.
Harris & Benedict Equation:
• For men: BMR = 66,5 + (13,75 x weight in kg) + (5,003 x heigh in cm) – (6,775 x age)
• For women: BMR = 655,1 + (9,563 x weight in kg) + (1,850 x heigh in cm) – (4,676 x age)
Mifflin-St Jeor Equation:
• For men: BMR = (10 x weight in kg) + (6.25 x heigh in cm) – (5 x age + 5)
• For women: BMR = (10 x weight in kg) + (6.25 x heigh in cm) – (5 x age – 161)
There is week point in the equations but BMR is so useful in your training and diet so we use it anyway. To get more accurate BMR than this equations you have to use complicated and expensive machines.
If you can calculate how many calories your body needs in total rest, you can guess the total daily calorie needed when active. The total daily calorie need when active is the BMR value multiplied by a factor between 1.2 and 1.9, depending on activity level.
By knowing how many calories you burn, you know how many to consume.
This is very useful if you want to change your body composition like gaining muscle mass or loose body fat. If you want to gain muscle mass, a part of that is to eat more calories than your body use for life-support and daily activities. If you want to loose body fat, a part of that is to eat less calories than your body use for life-support and daily activities.
What about the week points?
One week point is that anaerobic exercises, such as weight-lifting, indirectly lead to a higher BMR because they build muscle mass, increasing resting energy consumption. The more muscle mass in the physical composition of an individual, the higher the BMR required to sustain their body at a certain level. Same goes for body fat, but in the other direction. More body fat lower the BMR. The body composition affect the BMR. And the body composition is not calculated in any of the two formulas for BMR.
Another week point is that – a long time low calorie diet – can reduce BMR by as much as 30%. During a low calorie diet the human body will lowering energy levels, up keeping of body physique and cell reproduction in body cells like skin, muscle and organs. The BMR will become lower. This is nor calculated in the BMR calculation.
Conclusion:
BMR have week points. There is factors that effect the result thats not in the BMR calculation and therefore the answer can be incorrect. But BMR is so interesting so it should be used anyway but one should know that the calculation is not 100% accurate.
