Newbie with a Baseline Metabolism Question

[runnerbill]

Hi all,
As you can see from my login that I am a runner. All distances but specialize in Half Marathons and am looking at a tri next summer.
I lost 120 pounds in the last 2 years but need to address nutrition more carefully. I have been on Fitday for 2 weeks and lost 8.5 pounds as of yesterday.

My running average right now is 40 K a week but goes as high as 120 K during racing season. exercise never the problem, nutrition is.

My question is as you get closer to your goal does fitday calorie restriction change with you or do you have to manually adjust it and if so how. I am using the free version at the moment.

[RunbikeSki]

Hi Bill,
I'm a runner too, but not nearly as dedicated as you are - wow. Big congrats on losing over 100 lbs - well done!

I think I understand you question, so I'll give it a shot. Your calorie requirements are based on you current weight. The heavier you are, the calories it takes to keep your body running. (Something I think is tremendouly unfair to those of us who have lost the weight ). You enter you weight under the weight tab and it will be incorporated into the calculation. So, yes, you will need to manually change it as you lose the pounds. Once that is done all of the other cool tools should fall into line.

Does that help? If not let us know and I or someone else will give it a stab.

[VitoVino]

Originally Posted by runnerbill

My question is as you get closer to your goal does fitday calorie restriction change with you or do you have to manually adjust it and if so how. I am using the free version at the moment.

Hi Bill, Welcome to FitDay.

Great question. The software is very robust and adjusts on the fly.

What you are asking about basically is Baseline Metabolism. And Baseline Metabolism is factored into Calorie Balance so the short answer is, as you get closer to your goal FitDay does indeed adjust your calorie restriction.

RBS supplied a great answer. To add to that, "to estimate your baseline metabolism, FitDay uses a formula based on your weight, height, sex, and age."

Obviously your adult height and sex are static (although the height is a dynamic parameter for youths who are still growing and using this software) while your age and weight are not. Therefore, besides your metabolism decreasing with weight lost, it also decreases with age. But not by much.

As an example, a 31 year old male at 5'9" and 145 pounds has a Mifflin Equation equal to 1602 calories per day. When 6 months older, this male now has the Mifflin equal to 1600 calories a day. Losing weight is really the big factor in your Baseline Metabolism, but age is worth noting.

If you want more accuracy in how FitDay calculates your Baseline Metabolism, you'll need to weigh yourself more often. Depending on how much weight you're dropping per week, every 3-4 days of entering your weight should suffice.

In addition, many of us have also found that adding nightly sleep as an "Activity" gives a more accurate reflection of daily calories burned.

Finally, I've found that FitDay's Baseline Metabolism is the same as others that can be found on the web. I compared my FD BMR (1447/1449) to here:

Calories per day/Baseline Metabolism

and the above came out to be 1448. Pretty darn close, in fact, it splits the difference between the Mifflin and Harris-Benedict Equation.