How do you calculate work (KJ) and Power (W) when jogging on a treadmill?

Question

The following is known...

The Weight of the Person, The Angle/grade of the Treadmill, The Time that they are on the treadmill, The velocity of the treadmill.

How do I calculate Work in Kilojules and Power in Watts after my workout (which may vary in time, grade, velocity and distance? (my weight is not moving too much!!!).

Answer 1

Lets work an example, which provide the equations.

• Vertical displacement = % grade x Distance
• Treadmill speed = $200$ m/min
• Percent Grade = $7.5\% ~\text{or}~ 0.075$
• Exercise time = $10$ mins
• Total vertical distance traveled $= 200$ m/min $\times 0.075 x 10$ mins = $150 m$
• Work = body weight (kg) x total vertical distance traveled = $70 kp \times 150 m = 10,500$ kpm or ~$103$ kilojoules
• Power = work / minutes = $10,500 kpm / 10$ mins = $1050$ kpm/min or Watts

Answer 2

the calculation anove describes how to calculate the Work done ON the machine. However the Work done BY the body, i.e. Kcal burned is different. Each machine, elliptical, treadmill, rower, has a different efficiency for translating work done on the machine into calories burned by the body. For ellipticals, this number is about 7, i.e., multiply the work on the machine, expressed in Kcal by 7 to get the approximate Kcal burned by the body.