What made Michael Johnson a world-beater? His upright running technique did not appear fast until we appreciated the distance between him and second place! To run faster do we emulate him? Many have tried and invariably failed. Does Johnson know something we don't?The most common response to the thought of stepping up the pace is to put more effort into the stride. If the legs are already being over worked due to a less than efficient technique, the centre of the brain (motor cortex) that initiates the action has to send more impulses adding to the traffic in the feedback loop.

We have the sensation that we are running quicker because of the increased effort, but are we using our energy efficiently?The next time you want to increase your speed try the following method. Initially, when you have decided to quicken the pace, observe what you normally do to achieve this.

After a minute, slow down to a comfortable jogging pace and again think about raising the pace. This time do not think about running faster but instead just move your arms quicker. If we think of only moving the arms faster, requiring less energy, the legs will match the speed. Try the exercise and experience the difference.

The first time you speed up you will use your usual habitual method, the second will feel different because it will be unfamiliar. A recent study at Harvard University titled:? aster top running speeds are achieved with greater ground forces not more rapid leg movements? Weyand et al (2000) found that runners reach faster speeds not by repositioning their legs more rapidly in the air but by other means.

Head of research, Peter Weyand explains: - When you see someone running at top speed, his or her legs and arms are swinging all over the place. There is just not enough active muscle power available to account for all the motion you see taking place. So where does the force come from? To determine what limits top running speed, thirty-three runners of varied ability were monitored performing at different speeds.

Surprisingly the amount of time taken to reposition the leg between steps (swing time) was approximately the same at top speed for all runners. The slowest runner? swing time almost matched that of the 1996 Olympic 100 metre champion, Donovan Bailey!So if the swing time is not a factor, how do the faster runners achieve higher speeds? The researchers discovered speed is determined by the amount of force applied to the ground rather than how rapidly limbs are moved through the air.

The greater the force, called the support force (SF), coming down through the body to the ground results in a greater force pushing back up, called the ground reaction force (GRF). Remember Newton? third law of gravity! So those runners putting more into the ground got more out of it.

Peter Weyand again: - Much of the work of running is done through passive mechanical processes, in which tendons and muscles act though elastic rebound, much like springs uncoiling, the uncoiling delivers the power to swing your legs. At first this seems wrong because surely to run faster we need to move the legs quicker. This study suggests that extra effort applied to moving the legs faster may not therefore be the most efficient way to increase speed.

The upward thrust of the GRF is translated into forward motion by the action of the hip, knee and ankle joints. If the act of trying to move the legs faster leads to unnecessary muscle activity, joint movement will be impeded therefore reducing the leg? efficiency to perform its task. When we run faster obviously the legs move quicker but this should be a result of a greater force pushing the leg back up from the earth (a recoil action).

For example the harder you throw a tennis ball at the ground the higher and faster it bounces back up. The faster a leg comes up from the earth, the quicker it comes back down. The paper summarises the results by stating:We conclude that human runners reach faster top speeds not by repositioning their limbs more rapidly in the air, but by applying greater support forces to the ground.

The study also found how the fastest runners achieve the characteristic longer strides. It has been known for many years that longer strides meant faster running. Coaches encouraged sprinters to practice taking longer strides and devised exercises to strengthen appropriate muscles (many of which lead to injury).

This now appears to be wrong. Trying to lengthen the stride length decreases a muscle? ability to apply the support force required to get back up for the next step. Runners are not faster because they take longer strides. It is the other way around; runners take longer strides because they are fast. They are fast because they apply greater support forces to the ground allowing them to spend longer time in the air, hence the longer stride.

So if the secret to achieving greater speed is to apply more force to the ground, how do we go about doing it? I suspect that in the light of this research there will be coaches looking to strengthen the muscles that push the leg downward. However is this the right approach? Whilst muscle strength is a factor, it could prove to be detrimental to performance if all that strength is misapplied.

In the act of trying to drive the leg down, the athlete will increase the risk of injury due to increasing the amount of stress placed on the joints. It may also reduce the recoil action if the joints are not allowed to move freely. I believe one factor is balance. If the body is off balance the application of the support force is impaired by unproductive muscle activity holding us up instead of allowing force to go down.

You can test this by leaning backwards as you run. If we can reduce interference with our balance mechanisms to an absolute minimum balance will take care of itself. Another aid to applying greater support forces is to swing the arms faster (as discussed earlier). Freeing up the shoulders and moving the arms quicker and wider will increase force and also I believe activate the segmental rolling reflexes that coordinate the upper and lower limbs.

Perhaps we can now understand why Michael Johnson? upright style is a world-beater. To run faster we should do as little as possible. Our? fforts?are more likely to impede free movement. Remember; less is more!Roy Palmer is a Teacher of The Alexander Technique and author of The Performance Paradox: Train Smarter to enhance performance and reduce injury.

More information can be found at http://www. artofperformance. co. uk

He works with sports people of all abilities to recognise and overcome performance-limiting habits.

Author:
Roy Palmer