Even if you're naturally fast, you can always get faster with focus, training, and by following these steps.
Step 1: Warm up Begin your training routine -- and warm up on race day -- by jogging about a half mile.
Step 2: Train for "explosiveness" Add a plyometric routine to your workout. These bounding and jumping exercises generate explosive muscle power, which you need to explode out of the blocks.
Step 3: Add resistance training Tie a three-foot-long rope to a circular barbell weight and put the weight on the ground. Tie the other end of the rope to a belt, and buckle the belt around your waist. Practice running while dragging the weight behind you. Increase the weight as you gain strength.
TIP: Strengthening your core -- both abs and lower back -- will help you run in a straight line, which will also shave time off your 40.
Step 4: Do drills Do drills that improve reaction time and your technique. For example, have a friend or your trainer stand a few yards in front of you, out of your way, and toss a tennis ball in your path at the same time you start running. Run to catch the ball before it hits the ground.
Step 5: Train the first 10 yards A good finish requires a good start. Do drills that target your start and first 10 yards -- or five or six strides. Check your starting stance, and make sure your first stride is two and a half times your leg length. Extend forward out of your starting stance, rather than standing straight up.
Step 6: Adjust your arms When practicing your sprint, pay attention to your arms. Bend them about 90 degrees when they're lowered and about 120 degrees when you lift them. With each step, pretend you're reaching into your pocket with your opposite hand for a peanut and then tossing it into your mouth, keeping your elbows as close to your sides as possible.
Step 7: Relax On race day, you may be nervous before the run, but learn to relax while you're running. Tensing your face, neck, and shoulder muscles will slow you down.
FACT: At 4.12 seconds, Bo Jackson clocked one of the fastest 40-yard dash times ever recorded at the NFL Scouting Combine.