New Thoughts on Acceleration- Drilling down Air Time


New technologies such as some of the optical scoring from Microgait is going to be very useful down the road. Often the video clues are not enough to make decisions besides breaking down flight and contact times. Drilling down further what is happening during hip flexion on recovery and the stiffness qualities during foot strike is going to help coaches see what to encourage and what to leave alone. Each acceleration approach is unique to the strength and body type of the athlete and is more of an art than science, unlike top speed that tends to have better measurement approaches.

Reducing air time to the minimal needs is not easy. You can’t do this with a camera only, as actual IR sensors are a must to get not only distance, but the stance duration and the calculated air time. The first three steps are vital to get down, as after the first three steps things tend to fall in place. The start and first few strides are very artificial and need to be ingrained as they are not 100% natural. Block work at high levels still can be improved with video analysis and more important time analysis with what is going on. One simple way is to mark the track and get specific distances of the first three steps as well as 10 meter splits.

Resistance work is not an enigma, but each load percentage past 10% creates a unique EMG activity change to the ankle joint. Loads of 10-20% have had incremental changes at every 2% of loading change, and I believe coaches will be looking at stance time and tibial motion in the next olympics in Rio. General acceleration abilities are for HS to college athletes, but those trying to get in the 6.6 range and faster can benefit on see how those foot strikes are being applied. Some master coaches have a great sense of this application, but most mortals need a good camera and a table of each step to ensure one isn’t loosing .03-.06 on air time. Some research shows that light resistance reduces hip flexion because nobody can ride the glide with a towed weight. Also when one rides the glide an punches too much with the knees, postures get vertical from the swinging of the foot forward. Too much air time allows the foot to cast out and over stride, creating a drastic and too vertical of a shin angle. Athletes that are not globally strong or locally stiff at the ankle will not be able to physiologically and physically push, not matter how good the cueing is.

Foot mechanics via structural and spike plate design really decrease the potential of elite sprinters. From some of the sport science studies done at the national level with some federations, a spike plate is a static and rigid design, not allowing for gear ratios of the forefoot to adjust as much as needed. This can be observed with Asafa and Mo with head on views and the excessive lateral sway of the knee. The body is amazing in able to accommodate to carbon fiber, but new composites in spike plates are going to be necessary to allow athletes to hit great anatomical positions during acceleration with the metatarsals, not just keeping things stiff during top speed. I predict changes in cleat and football boots down the road as well, as we are seeing a rash of injuries because of the new and improved technologies. Minimal support is needed, as some of the wannabe vibram shoes are causing a lot of harm in athletes with the increase of stress fractures in the toes.

Hill sprints are still great ways to adjust the stiffness of the ankle joint, and many times athletes tear achilles from doing stair running because the load is too much. I think we should start calling it slope sprints intend of hills because we start seeing a conditioning and toughness approach instead of speed. Fast athletes are like blades, just because they are made sharp doesn’t mean you don’t need to sharpen them. While god or mother nature may have made them talented, talent without support leads to a loss in ability. Hills are often safer on the muscles because of speed and contractions but they are also more likely to load the ankle joint more so be careful.
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Carl Valle

Carl Valle

Track & Field Coach
Carl is an expert coach who has produced champions in swimming, track and numerous other sports. He is one of the foremost experts in the fields of nutrition and restoration.
Carl Valle

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