Improve your speed by improving your hamstring strength and conditioning. Every fast athlete has powerful hamstring muscles. You need to strengthen your hamstring muscles all year to avoid injuries.
The glute ham raise is an advanced strength exercise for the hamstrings. There are few injuries as bothersome and harder to recover from than hamstring injuries . Prevention of hamstring injuries is the best solution. Similarly, weak hamstrings can lead to other serious injuries.
You can execute the glute ham raise with the assistance of a partner holding down your feet. The partner might also need to assist you in raising up. YOU WANT YOUR HAMSTRINGS TO DO THE WORK!!
Also, try these flexibility and strength exercises for your hamstrings:
Hamstring Flexibility - walking lunges, resistance band eccentric stretch and static stretch (static stretch should be done after workout or game).