Could moving in reverse create a faster athlete?
Typically sprinting at a high intensity with appropriate amounts of rest between each set of sprints is the best way to increase sprinting velocity. The body adapts to the stresses it is put under, so running at high speeds will increase the speed threshold. A few drills can be done at a low intensity for a warm-up or as drills during a speed training session—starting at walking, low-level plyometrics, rhythmic exercises, and finishing full-on running.
Why trade traditional sprinting drills that have been proven to work for decades? You shouldn't. "Don't fix what isn't broken", but supplement these drills into a program to increase the strength of the Stretch Reflex that occurs during the muscle actions of sprinting by eccentrically loading those tissues. This is similar to adding eccentric/isometric focused lifts in the weight room to have a more vital Bench Press or Back Squat. These drills will help advance an athlete past a plateau or to the next level of their speed development.
Reverse Walk Series
The first drill is the Reverse Walking Series: 2 Step Drop. This drill is started on the balls of the feet, standing tall, taking two steps backward, and on the third step, dropping down into a narrow stance, lunge rapidly and sticking it for a second or two, making sure to keep heels off the ground in an active foot position. This stance resembles an athlete starting a linear sprint in a two-point stance. This is repeated for either a certain number of reps or distance. This drill can either be used as movement prep during a warm-up before a speed session. Or as a way to activate the foot before a strength session. The more advanced an athlete becomes, the more they can stabilize at the foot and ankle during the walk. This can be progressed to a jogging tempo but still used in the same capacity of prep before a workout.
The next intensity past the Walk Series is a low level plyometric, Reverse Crouch Alternate Bound. In a quarter squat with hands-on-hips, the athlete will jump backward onto a single leg, landing with the foot's ball and sticking the land for a second before stepping back down with the other foot. This jump should not be maximal because the body is forced to either counterbalance the force too much by leaning forward or letting the momentum pop them up into an upright position, either way losing the stable crouch position. Also, the intensity of a maximal jump and landing in the desired manner can be too much for the tissue's capacity. This jump should be as linear as possible, straightening the leg as much as possible to lengthen the hip flexor and activated the hip extensors, with little to no diagonal movement. If there is a significant amount of lateral movement with the goal being as linear as possible, other implications of tight Glute Medius or weak Adductor muscles can lead to corrective work.
This drill can be increased in tempo by adding multiple bounds before the stick. Also done as tissue prep during a warm-up or can be done to assess an athletes' body's capacity to stay linear. This drill's main goals are the stretch/lengthen the muscles of the leg that is stepping back, keeping a crouch or athletic posture, and landing on the ball of the foot. Just like the Reverse Walk Series, this can be done for reps or distance.
Reverse Rhythmic Drills
A way to add more coordination and complexity to traditional sprinting mechanic drills such as A-Runs/High Knees or Cycling/Claw drills adds rhythms or skips to them in the form of an A-Skip or B-Skip. Similarly, adding rhythmic tempos in a reverse manner will add complexity and increase the leg muscles' muscle actions, especially the foot. The two drills I have applied in training my athletes are Reverse A-Skips and Reverse Butt Kick Skips. Both require the intent to drive the leg and foot down AND back to create the momentum to move backward while creating stiffness in the foot. Because of the movement's reverse actions, the body's posture will want to start to lean back into the Thoracic and Lumbar Extension. The trunk must be strong enough to hold a tall and level posture just as it is imperative to move forward during top-end speed. Adding band or bungee resistance around the waist can add intensity to the movement while giving external cueing to fight the resistance backward.
The most intense drills are the fastest moving. The first one is Reverse A-Runs/High Knees. Begin with doing single switches, always coming to a balanced knee up toes up (hip/knee flexion and dorsiflexion) position while the bottom leg stays on an active foot. Increased complexity to double or triple switches on coaches call or when an athlete is ready eventually progresses to continuous switches for time or distance. Maintain the same posture as if moving forward during traditional A-Runs. These are used to mimic the piston action of acceleration.
The second drill is Reverse Sprinting or Reverse Running. This is the most intense drill due to the speed of the stretching of the hip flexors. This is done exactly as it sounds, run as fast as possible backward. This is not a backpedal movement, meaning quick steps as a defensive back does in football. The movement is done with a 'push and reach' mindset, pushing maximally off the stance leg and kicking the calf up toward the hamstring and kicking back with the swing leg. Don't let the athlete lean too far forward or it can allow too much hip extension and be a dangerous stretch on the hip flexors. Reverse Sprinting is used to mimic top-end speed mechanics.
In conclusion, these are just a few adaptations of drills that can be done in a Reverse Series to help improve the body's muscle actions during sprinting to help create more elastic and stable mechanics to be faster. These drills should be coupled with a light jog back to the starting point to bring the tissue capacity up to the new ceiling that was just introduced during the Reverse drill. A couple of notes that should be noted: First, although the focus is linear movements, some of these drills can be done in more lateral movements to help with a change of direction. Second, these drills can be performed barefoot safely and effectively, but due to the intensity volume should be decreased. Last, as some may notice the importance of staying on the ball of the foot during the drills; Active Foot protocols are becoming more imperative in weight room training, but utilizing dynamic Active Foot such as these have great carry over to athletics.