Basal Metabolic Rate - Burn Fat while you Sleep

How your Basal Metabolic Rate will help you Lose Weight

Your Basal Metabolic Rate (BMR) is the rate at which your body burns calories throughout the day to maintain normal body functions such as digestion, blood circulation, respiration etc. Your Basal Metabolic Rate will generally constitute the highest form of calorie expenditure and when combined with the energy your body expends exercising and keeping warm or cool (thermo-genetic effect), we can determine your ideal daily calorie intake.

A calorie is the unit measure used to express the energy value of food. Our body’s primary fuel sources are carbohydrates, fats and proteins. Carbohydrates and proteins have 4 calories per gram, while fat has 9 and alcohol 7 calories per gram. (1 calorie = 4.1855 joules).

Calculate your Basal Metabolic Rate (B.M.R.)

To calculate your Basal Metabolic Rate, the Harris-Benedict formula uses height, weight, age and gender. This equation has its limitations though as it does not take lean muscle mass into consideration and so the results will be inaccurate for extremely muscular (it will underestimate) or obese (it will overestimate) people.

Men:

BMR = 66.47 + (13.75X _____ Wt) + (5 X ______Ht) - (6.76 X _______ A)

Women:

BMR = 655.1 + (9.56 X _____ Wt) + (1.85 X ______ Ht) - (4.68 X ______ A)

where Wt  = weight in kilograms, Ht = stature in centimeters, and A = age in years¹

By calculating your Basal Metabolic Rate you can determine how much energy you need to consume to gain, maintain, or lose weight. Anything that you eat over and above your Basal Metabolic Rate must be used or it will be stored, potentially as fat. Alternatively, if your energy expenditure exceeds consumption for the day, then your body will draw on stored fuel sources to meet you energy requirements.

For example, if a 30 year old woman, 170cm in height and weighing 80kg (BMR = 1870) consumes 2000 calories a day, she has a surplus of 130 calories that must be burnt off through physical activity or stored as body fat. A 3500 calorie difference between dietary intake and energy expenditure which can be accrued overtime, is necessary to gain or lose half a kilogram of fat.

Factors that influence your Basal Metabolic Rate (B.M.R.):

• Genes – inherited Basal Metabolic Rate from your parents
• Age – Basal Metabolic Rate declines with age due to loss of muscle mass
• Gender – males Basal Metabolic Rate is faster than females due to greater muscle mass
• Muscle mass – the more muscle you have the higher your Basal Metabolic Rate as muscle burns more energy than fat tissue
• Exercise – increases Basal Metabolic Rate directly and via its effect on muscle mass
• Crash diets or starvation can reduce you BMR significantly
• Hot or cold climates can affect Basal Metabolic Rate as your body has to work harder to maintain a normal temperature.

It is important to understand that your Basal Metabolic Rate will decrease if you lose muscle, but not if you lose fat. For those trying to lose weight, it is essential to follow a healthy eating plan and structured exercise programme that stimulates muscle development. Crash diets ultimately end up drawing on your lean muscle mass as fuel, which lowers your metabolic rate. Consequently when you stop dieting, you end up putting on fat more easily than before you started, because a reduction in lean muscle mass has lowered your basal metabolic rate.

If you look after your body through a combination of good quality food and exercise then your weight will reflect this over time. There’s no such thing as a quick fix. True results come with hard work, smart choices and planning.

By Hamish Abbie BPhEd, BComm, CHEK L1, XLR8 Coach, REPs - 01/06/2007

Pulse Personal Training – It’s About Success - www.PulsePT.co.nz