The Force-Velocity Curve is a well known classification system in training. The thumbnail graphic included with this lesson provides a clear and simple example of the relationship.
Absolute, or 1-rep max, strength is at the top of the vertical or "y" axis. Top speed, or maximum velocity, is on the right of the horizontal, or "x" axis.
This graph allows us to quantify output in sports and training quite easily. Heavy, relatively slow movement builds strength, and unloaded fast motion represents speed. However, these entities are uniquely related. As soon as we move loading even slightly away from maximal and begin to attempt to move a weight (or other implement) more rapidly, we are increasing RATE OF FORCE DEVELOPMENT. As we progress along the curve, our emphasis increasingly focuses on not how much we can move, but how quickly we can move it.
Think of a heavy, slow, grinding 1-rep max bench press. That's Strength. Now picture a more explosive lift, like a barbell power clean in which you really focus on accelerating the bar up against gravity. That's Strength-speed. Get behind a loaded sled and push it 20 yards as fast as possible, that's a hybrid of strength and speed and we call that mid-range of the curve Power. Now throw a very light medicine ball as high or far as possible. That's Speed-strength (greater emphasis now on speed). Finally, run unfettered on a slight downhill at your very highest level. Pure Speed.
Another way to envision the transition from strength through power to speed is to look at tethered running using a drag rig. Let's say you start out by hooking up a bunch of sandbags such that you can only move the rig a couple steps with max effort. Again, that's strength. Then you gradually remove load (still giving a top effort each time) until you eventually ditch the rig and sprint with no resistance at top speed.
We can come up with endless examples of exercises and athletic outputs which can be placed along the Force-Velocity curve. The point to recognize here is that strength and speed training complement each other, and we blend different elements along the curve depending on our specific training goal.
This is one reason why we use a progression in our Training Tribe Annual Plan in which the periodized blocks move from Strength (and hypertrophy) to Power to Speed. By following this order, we can maximize the gains and minimize injury risk in our team members as we graduate along the Force-Veolcity curve through a major part of the year.