So, how do we train our bodies to best take advantage of this process? Progressive resistance training. With progressive resistance training, such as you might get from any typical strength training regime - running with added weights, for example - you better develop the synaptic connections to each motor unit. This in turn allows you to activate more force more quickly, resulting in greater total and explosive strength - crucial factors for any athlete (Delavier, 2001).
Another factor comes into play when we look at complex movement patterns, the sort that make up the backbone of tennis play. We aren’t built with the innate programming necessary for an excellent serve—aside from walking, running, swimming, and few other basics, we have to input the process over time (Adams, 1984). That means repetition of the ideal movement over and over, so that your motor cortex absorbs the motion and adds it to that list, alongside running and swimming.
This is why it’s crucial to train right from the beginning, preferably when you’re in top condition and your errors are at a minimum. Otherwise, you might just program the errors into your brain, where they become far harder to overwrite without truly excessive efforts (Adams, 1984).
So, remember your brain as you develop your muscles. You don’t want to build a body without the proper driving force prepared; even if your muscles swell to preposterous sizes with poor training, they won’t offer nearly the gain of force and precision possible with good training methods.