biodex Biostep 2 - What are Exercise Calories?

NOTE: Biodex Ergometers support METs and aid exercise prescription for both
cardiopulmonary rehabilitation and medical fitness.
Knowing the maximum METs (rate of energy expenditure) and VO2 max (maximum
oxygen utilization capacity) of an individual is important for building an effective fitness
program.
What are Exercise Calories?
By definition, one calorie is the amount of energy needed to heat 1 kg of water by 1 degree
Celsius. A calorie is the equivalent of 4,200 joules. A joule is also a measure of energy.
When referring to exercise, calories are a measure of energy expenditure. Exercise calories
are the number of calories you burn when you perform specific exercises, such as walking,
jogging, and pedaling. Exercise calories are based on the following factors:
• your weight
• the type of activity
• the intensity level of the activity
• the duration or total exercise time
Exercise intensity measures the extra energy needed above the body's minimal energy
require ments, or Basal Metabolic Rate (BMR), to perform the activity. Because
measurement of actual exercise intensity requires oxygen uptake monitoring equipment,
Biodex can only estimate exercise intensity using standard formulas for different types of
activity. Thus, Exercise Calories are also an estimate.
NOTES:
1. Your BMR, or the number of calories your body burns at rest, depends on both sex and
weight. To calculate your BMR, multiply your weight by 11 for a male or 10 for a
female and then divide by 24 to get to your BMR in calories per hour. For example, the
BMR in calories per hour for a 30-year-old male weighing 180 pounds would be:
180 x 11 / 24 or 1980 / 24 = 82.5 calories per hour
2. Oxygen uptake, or VO2, is usually expressed as a rate per unit of body weight, or
milliliters per kilogram per minute (ml/kg/min).
Once you know the MET value for a particular activity, you can calculate the number of
calories burned per minute using the following formula:
Total Calories Burned/Minute = Duration in minutes x number of METs x 3.5 x weight in kg / 200
For example, the total number of calories burned in 1 minute by a 150 lb (70 kg)
individual at rest is:
Total Calories Burned Per Minute = 1 minute x 1 MET x 3.5 x 70 kg
/ 200 = 3.5 x 70 / 200 = 245 / 200 = 1.2 calories per minute
If the same individual engages in moderate physical activity with a value of 4 METs, for a
total of 30 minutes, the number of calories burned per minute would be:
Total Calories Burned Per Minute = 30 minutes x 4 MET x 3.5 x 70 kg / 200
30 x 4 x 3.5 x 70 / 200 = 29400 / 200 = 147 calories per minute
— 17 — EXPLAINING METS, CALORIES, & WATTS