Metabolic Equations Treadmill Energy Expenditure

Let’s take the man from the walking running section and continue through to find and prescribe his energy expenditure..

A 58-YEAR OLD MAN IS WALKING ON THE TREADMILL AT 2.5 MPH, UP A 3% GRADE. WHAT IS HIS VO2 WORKRATE?

speed = 2.5 mph × 26.8 = 67 m/min
grade = 3% or 0.03

So, since all the units have been appropriately converted, I have:
VO = 3.5 + (speed × 0.1) + (speed × grade × 1.8)
by substituting: VO2 = 3.5 + (67 × 0.1) + (67 × 0.03 × 1.8) = 13.8 ml/kg/min.


LET’S CONTINUE HERE.. HOW MANY KCALS DID HE SPEND IF HE EXERCISED FOR 30 MINUTES AT THIS LEVEL?


What is his absolute VO2 if his BW is 50 kg?

Absolute VO2 = Relative VO2 × BW
So, VO2 = 13.8 ml/kg/min × 50 kg = 690 ml/min, or 0.69 l/min.

How many kcal of energy did he spend if he exercised for 30 min?

Total VO2 = absolute VO2 × duration = 0.69 l/min × 30 min = 20.7  l.min

We know that 1 liter O2 is equal to 5 kcal of energy, therefore he burned 103.5 kcal.

How much fat did he burn in this exercise bout?

1 lb fat = 3,500 kcal, so he burned 0.03 lbs of fat.

How many sessions to burn 1 lb of bodyfat?

3500 / 103 calories per session = 34 sessions!