Former Tampa Bay Storm Line Backer(1994), Tony Vadlez talks aboud speed training. These are high intensity exercises designed to keep athletes light on their feet.
The V Drill
3 cones are place 5 yards apart in a triangle configuration. Assume starting stance at cone 1, sprint to cone 2, stop and back pedal to cone 1. From there, srpint to cone 3, stop and back pedal to cone 1. Repeat this procedure for a solid 10 minutes (maybe 2 to 3 minutes for beginners).
The T Drill
4 cones are placed 5 yards apart in a T shape (1 cone at the starting position and 3 cones in a line perpendicular to cone 1). Sprint 5 yards to cone 2 (the center cone of the head of the T shape), stop and shuffle 5 yards to cone 3 (the right most cone). From there, shuffle 10 yards to cone 4 (the left most cone). From there, shuffle 5 yards right to cone 2. Then, back pedal to cone 1. Repeat this drill for 15 minutes (3 to 4 minutes for beginners)
The Shuffle Drill
3 cones are placed 5 yards apart in a straight line. Assume starting stance at cone 1, sprint to cone 2, come to a stop and sprint back to cone 1. From cone 1, sprint to cone 3 then back to cone 1. Repeat the drill for 8 minutes (beginners try for 1 minute).
Mister Valdez explains that the abrupt changes of intensity from sprinting 5 yards, stopping, sprinting 10 yards, stopping, shuffling, and back pedaling work the leg, hip, and abdominal muscles in such a way that the body becomes able to move in any direction flawlessly, and quickly. These may sound like simple exercises, but when performed for minutes at a time, and in the midst of several other exercises, weight training, and actual game drills, they become down right brutal in the Tampa Bay heat.
All these drills, and more, can be found on Youtube.
Always check with your physician before starting a new exercise regimen.