In a previous post (Energy Balance With Three Eye Opening Examples), I delved into the idea of energy balance with a little bit of science. As I have become more in-tune with my body through this training, I am rethinking my energy requirements due mostly to the results of research into the subject. And now that the need for energy balance has been established, it’s time to get into the first component, resting energy expenditure (just using the word expenditure in a post makes me feel smart by the way).
Three Components Of Energy Expenditure
For all intensivepurposes, our body uses energy to do three things: survive, move, and digest food. That’s about it. Let’s put it in bullet points to make more clear:
- Survive = Resting energy expenditure (REE): this is the energy it takes for your body to do the normal stuff (i.e. breath, pump your heart, maintaining body temperature, etc.) while at rest
- Move = Physical activity: as the name implies this is the energy it takes when you move beyond rest and actually move.
- Digest Food = Breaking down the grub: the fancy term for this is the thermiceffect of food (TEF).
The first two use the majority of our calories and are of concern to us from an energy standpoint. The amount of energy used to break down food is insignificant by comparison.
Resting Energy Expenditure
This is the big one for me. It amazes me how much we don’t realize we eat. I won’t go into the obesity issue in the U.S. But, if everyone actually figured out this number, and tracked their caloric intake, I think they would have an eye-opening revelation.
Below is the Harris and Benedict formula to calculate your REE. This formula was first published in 1919 (see here). Revised over time, the following equation is more predictive for modern lifestyles (see here):
- REE, men (kcal) = 66.5 + 13.8 * weight (kg) + 5.0 * height (cm) – 6.8 * age (years)
- REE, women (kcal) = 655 + 9.6 * weight (kg) + 1.8 * height (cm) – 4.7 * age (years)
- The basal metabolic rate of healthy people can be estimated by formulae with an accuracy of ±20% (I)
Here Are My Numbers
Based on the information above, my REE is:
66.5 + 13.8 x 67.13(kg) + 5.0 x 180.34(cm) – 6.8 x 40(years) = 1,622.60kcal
That’s not a lot of calories! Obviously, this does not include physical activity and this number is more of an average than an exact figure. But think about the millions of people that sit behind a desk or a computer all day long and barely move. In the post mentioned above, examples were given about how extra calories could add pounds to your body without any extra movement added. We’re not even talking about the quality of calories at this point either. I will leave you to digest the implications.
Energy Equals Athletic Success
As a first time triathlete, this number as a basis for my required energy needs (think caloric intake) has implications on my success. We can estimate physical activity expenditures to multiply this number to see how much or little we need to adjust our intake for athletic success. That’s where the next post on this subject will begin.
- Almost purchased a Garmin Forerunner 935 over the Suunto 9. However, a Garmin Forerunner 945 is expected in about a month.
- Still riding the 1980s Batavus borrowed from a friend. Waiting on the funds to buy a bike of my own. Looking at Felt FR30 road bike or Felt B14 triathlon bike.
- Gotta get some riding shorts. Looking at these Sponeed Men’s Cycling Shorts.