Force referring to the load, or weight being moved and velocity being the speed at which it is moved. Here’s the part that I like, increase either one, force or velocity, and you in turn will have more power! An example, if you were trying to get more power into your bench press, to move more weight, you’d have to work both on the force and velocity aspects separately. For force you would load the bar with 85%-100% of your 1RM (one rep max) and try it push it as hard and fast as possible for 1-5 reps; in actuality you wouldn’t be moving the weight fast at all, but your muscles would be in a constant and maximum state of recruitment and excitivety, and you would be working very hard to move the load. For the velocity or speed aspect of power what you’d want to do is the same or similar exercise this time with only 50%-70% of your 1RM move it both concentrically and eccentrically (up and down basically) as fast as you can control for 3-5 reps.
I didn’t know about this little formula for such big results in the gym until I read my NASM CPT 4 book. Ever since though, I’ve applied it and made it the foundation of my training for the next 6 weeks and have seen great results; I’m definitely getting stronger. I go by a 5 set, 5 rep scheme for each exercise, and usually hit 3-4 different exercises for a body part(s) and they’re all compound movements. I prefer to work in one specific area, either work on force production or work on building velocity I don’t interchange them too much in a session. I definitely recommend anyone with some experience in the gym under their belt to give this a try, it may be something different and you and your body will benefit from it! Let me know if you have any questions and how it goes!