If you’re looking to change your body composition, then you need to understand thermogenesis and how it plays into your potential success. Thermogenesis is when your body burns stored fuel supplies – that is, calories – to generate heat.
The Basics of Thermogenesis
Thermogenesis can occur in three ways:
- Non-exercise activity thermogenesis, abbreviated as NEAT. So, this means physical activities other than your training (see NEPA below).
- Exercise-associated thermogenesis, abbreviated EAT. This would be your scheduled training plans.
- Diet-induced thermogenesis, or DIT. This would be your body dealing with eating, digesting, and storing of byproducts of digestion.
NEPA stands for non-exercise physical activities. This would include the energy expended preparing meals, walking at your job, typing on a computer, performing yard work, cleaning the house, shivering, and other low-intensity actions throughout the day.
Even though sitting on your butt or performing minimal non-exercise activities does not lend to optimal calorie burning, your NEAT/NEPA number can still play a role in whether you lose, maintain, or gain weight.
Every Move Counts
“Exercise” or not, everything counts. Even these low-intensity activities contribute to an increase in your metabolic (calorie-burning) rate. Cumulatively, all activities have an impact on the number of calories you need to survive in addition to your base-line daily calorie requirements.
“Being aware of and intentional about all these factors will help you determine the optimal balance of calorie intake and energy output relative to your goals.”
This baseline calorie requirement is known as your basal metabolic rate, or BMR. The specific number of calories required to keep you alive, to support internal organ function, and to maintain your existing muscle mass depends upon your body type and current muscle mass. Surprisingly, the baseline calorie expenditure to simply support your body is relatively high. Check out the following examples:
- Female – 38-year-old, 115lb/52kg, 5′-4″/163cm = 1,277 calories
- Female – 22-year-old 155lb/70kg 5′-8″/173cm = 1,545 calories
- Male – 55-year-old 200lb/91kg 6′-4″/193cm = 1,903 calories
- Male – 24-year-old 245lb/111kg 5′-11″/180cm = 2,331 calories
The Role of Your Diet
To get an idea of how changes in NEPA can compare to changes in food consumption and planned exercise, let’s look at some numbers.
Meal 1 – 416 calories
- 4 oz. pink salmon (168 calories)
- 1 cup boiled broccoli (55 calories)
- 0.5 cup cooked couscous (88 calories)
- 8 oz. 1% cow milk (105 calories)
Meal 2 – 768 calories
- 2 large scrambled eggs + 1 tbsp milk + 1 tsp oil (197 calories)
- 1 whole grain bagel (340 calories)
- 1 large banana (121 calories)
- 8 oz. orange juice (110 calories)
Meal 3 – 1,324 calories
- Bacon cheeseburger (Five Guys) (919 calories)
- 1.7 oz bag of nacho cheese tortilla chips (262 calories)
- 12 oz. cola (143 calories)
Meal 4 (Olive Garden) – 1,189 calories
- 2 breadsticks with garlic butter (280 calories)
- Grilled chicken Caesar salad (609 calories)
- Wild berry smoothie (300 calories)
The Role of Calorie Burning
Now, let’s look at planned training and NEPA calories burned in thirty minutes using two of the previous gender examples:
Female (F) – 38-year-old, 115lb/52kg, 5′-4″/163cm
Male (M) – 24-year-old 245lb/111kg, 5′-11″/180cm
For these two athletes, the following number of calories are burned:
- Circuit strength training: F = 222, M = 442
- Cycling – hard: F = 294, M = 588
- Running @ 7:30/mile: F = 344, M = 704
- Walking @ 4.0 miles per hour: F = 137, M = 282
- Walking @ 1.5 miles per hour: F = 51, M = 106
- Martial arts: F = 263, M = 538
- Yoga: F = 89, M = 183
- Racquetball: F = 252, M = 511
- Housework: F = 75, M = 170
- Grocery shopping: F = 68, M = 122
- Lawn mowing: F = 139, M = 283
- Driving: F = 50, M = 100
- Raking leaves: F = 109, M = 245
Given the above activity numbers, let’s put our examples into action in the following case studies.
Female Case Study
38-year-old, 115lb/52kg, 5′-4″/163cm, with a BMR of 1,277 calories.
- Meal 1 = + 416 calories
- Meal 2 = + 768 calories
- Meal 3 = Skipped
- Meal 4 = + 1,189 calories
Total calorie intake = + 2,373
Now, subtract these.
- BMR = – 1,277 calories
- 30 minutes of hard cycling = – 294 calories
- 30 minutes of martial arts = – 263 calories
- 30 minutes of driving = – 50 calories
- 30 minutes of housework = – 75 calories
- 1 hour of walking at 4 mph = – 274 calories
- 1 hour of grocery shopping = – 136 calories
Total calorie deficit = – 2,369 calories
Net total for the day = a 4-calorie deficit.
Male Case Study
24 year-old 245 pound/111 kg, 5′-11″/180 cm male with a BMR of 2,331 calories.
- Meal 1 = + 416 calories
- Meal 2 = + 768 calories
- Meal 3 = + 1,324 calories
- Meal 4 = + 1,189 calories
Total calorie intake = +3,697
Now, subtract these.
- BMR = – 2,331 calories
- 1 hour of circuit strength training = – 884 calories
- 1 hour of driving = – 100 calories
- 1.5 hours of walking at 1.5 mph = – 318 calories
Total calorie deficit = – 3,633 calories
Net total for the day = a 64-calorie surplus.
How Do You Rate?
Look at these facts and assess your daily energy expenditure of NEPA, and ultimately NEAT. Become vigilant about your total daily calorie intake, all physical activities engaged, and their duration. Being aware of and intentional about all these factors will help you determine the optimal balance of calorie intake and energy output relative to your goals.
More on nutrition and activity:
- Is Low Calorie Dieting Dangerous?
- Calorie Burn for Bodyweight Exercise May Be Underestimated
- The Right Way to Lose Fat: What to Eat
- New On Breaking Muscle Today
References:
1. Denzer, C.M. and J.C. Young, “The effect of resistance exercise on the thermic effect of food,” International Journal of Sport Nutrition and Exercise Metabolism 13 (3) (2003): 396–402.
2. Levine, J.A., “Nonexercise activity thermogenesis (NEAT),”Best Practice & Research. Clinical Endocrinology & Metabolism 4 (2002): 679-702.
3. Thermogenesis, accessed August 8, 2015.
4. Activity calorie calculator, accessed August 9, 2015.
5. Activity calorie calculator, accessed August 9, 2015.
6. Activity calorie calculator, accessed August 9, 2015.
Photos courtesy of Shutterstock.
