Question

Sarah has a BMR of 1775 and ingests, on average, 2390 kcals daily. She runs on the treadmill every day right after class for 45 minutes at 6.5mph, 3% grade. If she continues to follow her current eating and exercise regimen, will she likely lose weight, maintain her weight or gain weight? Her current weight is 70kg.

Answer 1

Sarah's BMR is 1775 which means that this is the minimum amount of energy which she requires for her basic regulatory function and activities like digestion, breathing as well as working and functioning of the heart. Hence, if she consumes less calories than this it will lead to losing of weight and consuming more calories without any activity with lead her to gain weight. Now, in her case, her daily calories consumption is 2390 kcals, and this means that her extra kcal consumed is 615kcal.

General formulae for finding out calorie burnt in the treadmill

Calorie burned per minute = (MET X body weight in Kg x 3.5) / 200

MET = [ (0.2 x speed) + (0.9 x speed x %grade) + 3.5]

MET = [ (0.2 X 6.5) + (0.9 X 6.5 X 3) + 3.5 ]

= 1.3 + 17.55 + 3.5

= 22.35

Calorie burnt per minute = (22.35 x 70 x 3.5) / 200 = 27.37

Hence, she works out for 45 minutes which means, the calorie she burns in 45 minutes =

27. 37 x 45 = 1231 kCal. Her body

This means that she is losing more calories than required and this will lead to losing weight which is not healthy. After consumption of food and after the BMR, she has 615kCal but she is burning 1231 kCal. This means her body is deficit of 616 kCal. This will lead to resulting weight loss