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Tuesday, June 29, 2010

Back to the heavyweight - How to basal metabolic rate

After my return home from Boston I was scared to set foot on the scale. Lack of exercise and overindulgence on food and drink would nudge the number higher. I have not been following my diet since the Pump and Run. I was a little under weight for that race – for obvious reasons but I rebounded more than I would have liked. Normally I bounce around 159 – 161 pounds. So I got on the scale after the travel and I was 8 pounds over my Pump and Run weight. That is over 5 percent in a month. I weighed 165 pounds which is the most this year!

Last year while training for ironman I dipped down to right around 155 pounds. I think it would be tough for me to get down there again. I have put on some muscle mass (not just from the pump and run) this year.
A full day of calories for many people!

Simply getting back into my routine has allowed for my body to respond and drop some of the weight. I have dropped 3 pounds in 3 days but that was the water weight. The next few pounds will be harder. It is time to get back on the horse and start the food journal back up. If you want to change something you have to know where you are. I actually have a pretty good understanding of where I am but the practice of documenting will get me on the fast track.

For those that do not know where to start, first you need to know your basal metabolic rate or more accurately their resting metabolic rate. This is the amount of calories you need to just live – nothing more. There are two formulas for calculating your BMR or RMR (for our ball park purposes these terms are interchangeable). The standard formulas are the Harris-Benedict and the Muffin. Where w – weight in kg, h – height in cm, and a = age. Let’s run the numbers for me – weight = 161 lbs = 73 kg, height 5’7” = 170 cm, age = 37.

H-B MEN = (13.75 x w) + (5 x h) – (6.73 x a) + 66 = 1670.74 calories

H-B WOMEN = (9.56 x w) + (1.85 x h) – (4.68 x a) + 655 = 1494.22 calories

Muffin MEN = (10 x w) + (6.25 x h) - (5 x a) + 5 = 1612.5 calories

Muffin WOMEN = (10 x w) + (6.25 x h) - (5 x a) – 161 = 1446.5 calories

These are all pretty close. This is the amount of calories you expend sitting on the coach, doing nothing. Next you can multiply the RMR by an activity factor.

Activity Factor Category Definition
1.2   Sedentary Little or no exercise and desk job
1.375 Lightly Active Light exercise or sports 1-3 days a week
1.55  Moderately Active Moderate exercise or sports 3-5 days a week
1.725 Very Active Hard exercise or sports 6-7 days a week4
1.9   Extremely Active Hard daily exercise or sports and physical job

So, for example if I take the RMR from the Harris Benedict calculation and I say that I am Very Active then I get – 1670.74 x 1.725 = 2882 calories per day. A Big Mac, large fries and a large regular soda is 1350 calories. Almost half of you daily allowance (if you are indeed VERY ACTIVE). If you are sedentary then you will only need 2004 calories and this meal is nearly 70% of your daily calories.

There have been numerous studies that indicate that it is not that important for the numbers to be extremely accurate; it is enough to see results if the numbers are just close. This is because the average person has no idea the number of calories in the food that they are consuming. Most people will grossly underestimate the number of calories in their food and then grossly overestimate the number of calories that they expend. They will see results if they can just get close to reality.

I remember a few years ago I was talking with a co-worker that was very overweight. She stopped at Hardee’s on the way to work and picked up a 6 pack of their little hamburgers. I think they called them slammers (I don’t think they make them anymore). I told her that the amount of calories and fat were more than she needed for the entire day much less than for lunch. She looked up the nutritional information on the website and said “See there, they are only about 100 calories each.” I took a look at the website and she was reading the chart incorrectly. They only weighed about 100 grams – not calories. The number of calories for each slammer was 280 calories (6 x 280 = 1680 calories). She still did not believe the numbers and was certain that the website was mistaken. Good figure.

Now if you look at that VERY ACTIVE amount of calories (2882) and try to eat only health, nutrient dense foods you will see that it is a whole heck of a lot of food. Do you know how many raw vegetables that is? How many boiled eggs? How about glasses of almond milk? How many pounds of lean chicken breast? When you eat healthy it is hard to eat enough!

Link to a BMR Calc

6 comments:

  1. Your last comment is pretty dead on. If you eat those calories all healthy... you will be eating ALL DAY!

    I will supplement higher calorie items when we are eating healthy in order to try and fuel my body properly.

    Sometimes its hard to maintain a balance. Great post. You are a wealth of information man!

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  2. Very timely post. While my weight is steady, I stopped logging my food and I know my diet sucks right now. I need to get back on that band wagon

    It will be interesting to hear your thoughts on the nutrition portion of the USAT clinic. The presenter doesn't take the traditional route. I found it very refreshing.

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  3. this is soooooooo informative and excellent.
    Thank you!!!

    I just bought the book "racing Weight" yesterday....hoping to improve my eating in any way I can. ;)

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  4. I read Racing Weight a couple of months ago - It was a good read.

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  5. Fantastic post, well written and informational. Thanks so much.

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