However, in most situations, simply moving the eyes will suffice. When your head is in motion it is more difficult to truly see the ball. In addition, your body lacks the stability to remain balanced and centered as you make contact with the ball. If there is one thing that you can do to improve the consistency of your strokes, following the ball with the eyes is probably it. As an additional benefit, you'll find that your peripheral vision improves when you practice this technique.
Tennis is a game that involves incredible bursts of speed.
No matter how accomplished you are as a player, sooner or later you are going to have to scramble to strike a ball. Many times when players are in a match they sense that they are not moving well and are not getting to the ball quickly. Big strides are really more counterproductive than helpful in most point situations. When training players on my college team, I try to spend more time on sprints than on distance running. Tennis is a game of sprints.