Your Basal Metabolic Rate (BMR) is the amount of calories that your body needs to lay in bed all day and do nothing. This is the amount of calories that you MUST EAT in order to maintain your body’s mass at rest. BMR does NOT include your daily activities.
To determine your BMR, you can use this equation (www.bmi-calculator.net/bmr-calculator/):
Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) – ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) – ( 6.8 x age in years )
After you know your BMR, then you need to find out what your Total Daily Energy Expenditure (TDEE) is. This is calculated by multiplying your BMR by your Activity Metabolic Factor (AMR). Your AMR is determined by your activity level during an average day. In general, most people will find that their AMR to be 1.2 (sedentary). It is important to remember that AMR does NOT include your calories burned through exercise.
Exercise increases your overall energy expenditure, and should be added to your TDEE. For example, I have a desk job, so I would be considered “sedentary”, but when I exercise, I can add the number of calories I burn during my workouts to my TDEE, therefore increasing my daily calorie expenditure. I find it easiest to view exercise as an “out of the ordinary” activity. Let’s make it simple:
BMR x AMR + calories burned through exercise – calories consumed = DAILY DEFICIT (DD)
I think that it is important that I make mention of the fact that I use a Polar F6 Heart Rate Monitor to determine the exact amount of calories that I burn through exercise. Whenever I workout, I wear it. This way, I get an accurate picture of my daily expenditure.
If you DO NOT have a HRM, I strongly encourage you to look into purchasing one. Check out this website: http://www.heartratemonitorsusa.com/ and use the coupon code “GALAXY” for an additional discount. In the meantime, here’s a breakdown of AMR:
Sedentary = BMR X 1.2 (little or no exercise, desk job)
Lightly active = BMR X 1.375 (light exercise, approx. 1-3 days/wk)
Mod. active = BMR X 1.55 (moderate exercise, approx. 3-5 days/wk)
Very active = BMR X 1.725 (hard exercise, approx. 6-7 days/wk)
Extr. active = BMR X 1.9 (hard exercise 7 days a week, physical job, training more than 1x/day)
If your AMR is anything BESIDES 1.2, here is the calculation that you will need to use:
BMR X AMR – calories consumed = DD
Creating a calorie deficit is actually fairly simple. In order to lose weight, you HAVE TO consume less than you burn. It all comes down to CALORIES OUT – CALORIES IN. In order to lose, you have to know what your deficit is every day (even your rest days), and you can accomplish this through journaling. In order to lose a pound a week, you need to burn 3,500 (1 pound = 3500 calories) calories in that week. This breaks down to approximately 500 calories per day. This can be accomplished one of three ways:
1. Create a 500 calorie deficit from your diet every day
2. Create a 250 caloried deficit from your diet and burn 250 through exercise per day
3. Burn 500 calories per day through exercise alone
There is actually a great article on one of my favorite websites, SparkPeople.com:
I am blogging about this because it is SO VERY IMPORTANT to understand that you MUST EAT in order to lose. If you do not consume enough calories, you body will go into a “starvation mode” where you will be losing muscle, not fat. If you continue to consume below your BMR for too long, then your body will eventually stop losing all together. This severely inhibits your metabolism and could potentially cause long term damage. I want everyone to understand that food is FUEL that your body needs, ESPECIALLY if you are working out.
