This is or could be a very handy method for developing power. What you will be doing is finding the amount of weight that is best for YOU when training for power. We all know (or some of us know) that the mathematical equation for power is p=w/t (power=work divided by time) and we will be using this equation. So you will need a calculator, a buddy with a stop watch, and you will need to know your 1RM.
Lets call the athlete in this make believe scenario "Bob" cuz it's a fun name to repeat endlessly when you use a weird voice. So "Bob" is at the gym with his bud "Harry" and Bob wants to find out what weight to use when he's trying to peak for power. Bob can bench press 300lbs for 1 rep, and Bob is no dummy and knows that when training for power it's best to start a little low in the weight department. Bob lays on the bench with 45% of his 1RM on the bar and bangs out 5 reps as fast as possible while Harry times the set. Bob does the 5 reps in 4.5 seconds with strict form. Harry punches the numbers into the calculator...
135lbs x 5 reps = 675lbs of work
600 / 4.5 = 150lbs of force per second (this is his power)
Bob ups the ante by adding 10% (50%) to the bar and bangs out 5 reps in 4.8 seconds
150lbs x 5 = 750lbs of work
750 / 4.8 = 156.25lbs of force per second
Bob's getting a little psyched about the numbers Harry is churning out, his power is going up so he ups the ante another 10% (60%) and bangs out 5 reps in 6 seconds.
180lbs x 5 reps = 900lbs of work
900lbs / 6 = 150lbs of force per second
Uh-oh, bobs power is going down so he already passed his peak power output. From this information Harry figures Bob should be training with 150-170lbs progressively when trying to build his power (from the weight he can bench the fastest and progressively increasing it to facilitate the need for greater power when training).
I used the bench press as an example but this modality could be used for other exercises as well but exercise a little common sense, if you would be flailing around with the weights then it's a poor exercise to use. I wouldn't do pullovers for example because when trying to go as fast as possible you would have to decelerate the weights yourself and maybe crush your legs (Im being a little dramatic but you can see my point). An exercise with a distinct beginning and end that can be done in a controlled manner that doesnt put you at risk would be best. Have fun with this and training in this fashion is best 1-2 times a week. I know I'll be hitting this up next time I'm looking to peak.
Happy Belated Thanksgiving!