Speed and acceleration are essential skills in most sports. Obviously in the sprinting disciplines but speed and the capacity to accelerate are also essential in most game sports in the moment that points are made or at the end of a race of longer distance.

The factors that help you improve speed and acceleration capacity are:

1. learning the optimal movement patterns you want to be fast at
2. automating the movement patterns you want to be fast at
3. training your body “machine” for efficient energy transfer at high speeds

Interval training for speed is mostly about the last one – improving acceleration capacity and maximum speed by fine tuning the “machine” physiologically.

That means, training your energy transfer system to be efficient for developing speed.

If you are a serious trainer or even athlete you should check out this
link which offers a complete speed training practical 35 page-manual and two hours of videos with the most efficient drills to improve speed and power.