We often look at training strategies in a bubble. We don't always consider the effect it will have on performance, both negatively and positively. We need to be sure we understand the impact of strength training on the goal we are after.
#1- Motor Recruitment
Lifting heavy weights definitely will cause a greater number of motor units to be recruited. This obviously aids in our strength gains. The more horses that show up to the party is better for strength.
When we strength train we need to have a stabile joints. This is accomplished through co-contraction of the musculature around the joint. As force is created and the system learns to contract is such a way that shearing is limited, if not, eliminated at the joint there is now a very safe and stabile joint.
#3- Speed of contraction
Not to be contradictory but the last statement mentioned co-contraction and stability of a joint. In this statement we are going to say in order for speed to reach its potential, let's say in jumping explosively, sprinting fast, or throwing hard, there needs to be less co-contraction so the agonist can generate great speeds without limitations from the antagonist. So we need an inhibition with an excitation to generate a well-coordinated fast limb movement.
#4- If we want speed to be the goal of our strength training we must have great motor unit recruitment, as mentioned, but we also need a high rate coding to occur. This is when the muscles fire extremely fast. This process will be most optimized with faster styles of lifts such as hang clean pulls or hex-bar jumps. The faster the muscle can coordinate and fire the greater the potential for speed.
Bam! There is that word again. You can do all the strength and power training you want. You can recruit muscles fast or slow. Stabilize joints or inhibit antagonists. The bottom line is you must have proper technique to get your biggest bang for the buck when strength training. Poorly executed lifts or exercises leads to lesser optimization of movement coordination- which can lead to potential injury. So, do it right or go home!