Power (Horse)

Talk about your lifts like you talk about trucks. (Just don’t compare the numbers...)

We all know what we mean when we talk about Power, be it in athletics or daily life, but what IS it, actually? Well, physics tells us that Power equals Work divided by Time, where Work is Force times the Distance moved.

P = ( F x D ) / T

I decided to grab a recent set of deep squats and play around to see if I could come up with some real numbers that would speak to a sense of Power.

1 set 10 reps 130 lbs

I took 130 lbs (Keep in mind pounds are already a unit of Force not Mass.) and added 196.2 lbs (90% of my body weight) and 44.1 lbs (the weight of the bar). Multiplying the total weight by 2.25 ft (the vertical distance the bar was pressed) and by 10 (the number of reps) gives 8331.75 foot lbs.

(130 lbs + 196.2 lbs + 44.1 lbs) x 2.25 ft x 10 reps = 8331.75 foot lbs of Work

A nice number to look at, but Work is not Power, and who walks around bragging about foot lbs pressed or pulled during a workout? Divide that number by the number of seconds it took to perform the set to get the Power output:

8331.75 ft lbs / 40 sec = 208.29 foot lbs/second of Power

If we multiply that by a conversion factor of 1.35, we get an average Power output of 249.7 watts.

Not bad! Vigorous rowing on an ergometer typically puts one at 200 watts, so this is a pretty good exertion. Still, doesn’t sound like tearing up the gym. That is because it is an average Power output, the wattage is high when pressing, and drops during the eccentric phase of the squat.

So, what about just one concentric contraction?

(130 lbs + 196.2 lbs + 44.1 lbs) x 2.25 ft = 833 ft lbs / 1.5 sec = 555.33 ft lbs / second

It turns out that a single unit of Horsepower is 550 ft lbs / second, so during one rep, I exerted 1.009 horsepower. HORSEPOWER. Now we’re talking!