Nordic Walking Guy found an interesting BMR calculator.
First, a definition: "...basal metabolic rate—the amount of energy expended while at rest in a neutrally temperate environment, and in a post-absorptive state (meaning that the digestive system is inactive, which requires about 12 hours of fasting)." In English, BMR is the number of calories burned when you're inactive.
Some observations on playing with the calculator.
- Concept of BMR calculations: "BMR is estimated with equations summarized from statistical data."
- BMR calculations are based on you your age, height, and weight.
- It lets you calculate your BMR according to any of 3 methods:
- Revised Harris-Benedict ("The Harris-Benedict Equation was one of the earliest equations introduced.")
- Mifflin St. Jeor ("The Mifflin-St Jeor Equation has been shown to be more accurate than the revised Harris-Benedict Equation.")
- Katch-McArdle ("The Katch-McArdle Formula is slightly different in that it calculates resting daily energy expenditure (RDEE), which takes lean body mass into account, something that neither the Mifflin-St Jeor nor the Harris-Benedict Equation do."
- Overall, "the Mifflin-St Jeor Equation is considered the most accurate equation for calculating BMR with the exception that the Katch-McArdle Formula can be more accurate for people who are leaner and know their body fat percentage."
Nordic Walking Guy selected the Katch-McArdle option and noticed something.
- Adjusting body fat percentage.
- When I input lower body fat percentages but kept my weight the same, the BMR went up.
- When I increased the body fat percentage and kept my weight the same, the BMR went down.
- Changing the body fat percentage while keeping my weight constant was another way of saying muscle mass increased or decreased.
- BMR went up because increased muscle mass burns more calories.
- BMR went down because decreased muscle mass burns fewer calories.
What does this mean?
- Integrate strength training to build some muscle mass so you can burn calories faster.
- Take advantage of diet.
- Here's an eye-opening statement: "For most people, upwards of ~70% of total energy (calories) burned each day is due to upkeep. Physical activity makes up ~20% of expenditure and ~10% is used for the digestion of food."
- Since you can't increase physical activity beyond a certain point without damaging your body, you'll want to manage your diet to create that calorie deficit needed to lose weight.
