Basal metabolic rate (BMR) refers to energy expended to maintain basic vital body functions such as respiration, muscle tone, and nerve function. BMR does not count the calories burned during exercise. How do the number of calories Miya burns during her 2-hour run compare to the other 22 hours of basal metabolism in her day?
a. She burns about one-third the calories in 2 hours of running as she does in 22 hours of basal metabolism.
b. She burns about half the calories in 2 hours of running as she does in 22 hours of basal metabolism.
c. She burns twice as many calories in 2 hours of running as she does in 22 hours of basal metabolism.
d. She burns about the same number of calories in 2 hours of running as she does in 22 hours of basal metabolism.
The correct answer and explanation is:
The correct answer is c. She burns twice as many calories in 2 hours of running as she does in 22 hours of basal metabolism.
Here’s the explanation:
Basal metabolic rate (BMR) refers to the energy required to maintain essential body functions like breathing, circulation, and temperature regulation. It accounts for a significant portion of a person’s daily calorie expenditure, typically around 60–75% of total energy use. The number of calories burned during BMR is based on the person’s body size, composition, and other factors, but it’s generally a steady, continuous energy expenditure.
When a person engages in physical activity, such as running, the number of calories burned increases significantly. For someone like Miya running at an 8-minute mile pace, the calorie burn can be substantial. In the example, Miya burns 709 calories per hour running at this pace. Over the course of 2 hours, she would burn approximately 1418 calories.
In comparison, BMR represents a constant energy burn over the other 22 hours of the day. If Miya’s total daily calorie expenditure is around 2500 calories, BMR would account for a large portion of this. Assuming her BMR is about 1500 calories for the day, it means that in 22 hours of basal metabolism, she would burn about 1500 calories.
When comparing the two, Miya burns about 1418 calories during her 2-hour run, which is approximately double the calories burned over the course of her 22 hours of basal metabolism (1500 calories). This makes answer c correct, since the physical activity during her run expends more energy than her BMR during the same period.