Muscle Sport Magazine

The Physics Of Weight Lifting, Part 5: Power

By Paul Becker – In our final installment of this series we’ll look at the formula for power and how to use it to make training more productive. The formula for power is: Force X Distance -:- Time. And is measured in foot-pounds/second.

In the last article we talked about work and how to calculate your workload for each workout, the first part of the formula for power is the same (Force X Distance), now we add the factor of time.

Now, for the purposes of muscle building we don’t mean increasing lifting speed, this just allows momentum to do the work and not the muscles. All exercises should be preformed slowly and deliberately.

As you will see when we talk about power, we are talking about training intensity. Let’s look how we can increase our workout power (intensity):

1) Use a full range of motion, for example let’s say your full range of motion on the bench press is 2 1/2 feet, that means1 rep (up and down) is 5 feet. And let’s say each rep takes 6 seconds (2 up and 4 down), if you use 250 lbs for 8 reps the power would be – 250 lbs X 40 ft -:- 48 sec = 208.3 ft-lbs/sec.


Now let’s say you cut 3 inches off the range of motion by not bringing the bar all the way down to your chest, this takes 1/2 foot off of each rep. So, if all other factors are the same, the above set now looks like this – 250lbs X 36 ft -:- 48 sec = 187.5 ft-lb/sec. With less range of motion power goes down.

2) Increase the weight you lift, for example, on our full motion bench press (250 lbs X 40 ft -:- 48 sec = 208.3 ft-lbs/sec) if next workout 5 lbs is added , it then looks like this – 255 lbs X 40 ft -:- 48 sec = 212.5 ft-lbs/sec. Lifting more weight increases Power.

3) Decrease time between sets, for example, 3 sets of bench using 250 lbs for 8 reps has the workload of – 250 lbs X 40 ft = 10, 000 ft-lbs. If these 3 sets are done in 10 mins (600 sec) the power is – 10,000 ft-lbs -:- 600 sec = 16.7 ft-lbs/sec.

If by decreasing rest time those same 3 sets are done in 6 mins (360 sec) then the power is – 10, 000 ft-lbs -:- 360 sec = 27.8 ft-lbs/sec.

About The Author: Paul Becker is a natural (steroid free for life) bodybuilder and fitness consultant. For more information on Bodybuilding and Bodybuilding Supplements visit his website at

Leave a Reply

Your email address will not be published. Required fields are marked *