Home Page
The Power Clean
The Physics
                Power
                Center of Mass
                Levers
Bibliography

Power is an important part of weight lifting and is what most lifters are concerned with. Lifters are interested in increasing their power output. To measure power you need to measure the amount of force applied to the bar and how far the bar travels to determine work and then measure the time it takes to accomplish the work.

This equation looks like this Power = Work/Time or more simply P = W/t

Now breaking power up into more basic measurable variables we find that power is P = (mass * acceleration * distance)/(time)

The mass is measured in kilograms and is what is lifted by the lifter. The acceleration is 9.81m/s^2 which is due to gravity. And the distance is the change in elevation from the ground to the lifters final position. Time is measured in seconds and is the duration of the whole process.

Our calculation will be in two parts: the first pull which puts the bar on your shoulders and the second pull which puts the bar at its final height.

FIRST PULL


SECOND PULL



So we will set h_1 equal to 1 meter and h_2 to .75 meters and say that the mass is 50 kilograms. We can estimate the work done by using Potential Energy. PE = mgh.

For the First Pull this is 50*9.81*1 = 490.5 joules. Then to determine the Power used we must divide the work by the amount of time it takes to move the weight to the first position. This normally takes about .5 seconds. So during the first pull the lifter is producing 490.5joules/..5sec = 981 watts of power.

For the second pull the time is normally about .75 seconds and  just doing the calculations P = ((50kg)*(9.81m/s^2)*(.75m))/(.75sec) which equals about 490.5 watts.

The total power produced during the power clean is then 1471.5 watts.

Do that at 3 sets of 8 reps and you'll be building muscle like a pro.