There are two exercises that I focus on with my athletes to improve their hip explosion. The first is HIP FLEXOR DRIVE, this is where you drive your hip up as high as possible and as fast as possible. You want to start with a staggered stance with the one leg behind the other. The back leg is then brought forward and up with an explosive and fast motion, you then return it back behind you. Pause for a second then drive it back up as fast as possible. You want to do it on each leg.
The second exercise is a MOUNTAIN CLIMBER DRIVE. How you want to start is get your body in a push up position. Then drive the one leg forward up to the chest as fast as possible. Return your leg back to the start possible, pause then drive it back up as fast as possible.
These two exercises will help produce a much better 40 time because you are focusing on your explosive power in your hips. Do these two exercises three times a week doing 3 sets of 12 reps. You will start to Unleash Your Potential.