Does speculation about the theory of running make any difference to how fast you can run? I have been observing and reading and talking and thinking about running mechanics since recommencing running again, about two years ago. Has this made any difference to how fast I run? The ultimate test is racing performance and I have run too few races to draw any definite conclusions. Furthermore, asthma has hindered my attempts to get fit, so even two years experience is scarcely enough to draw any definitive conclusions. However, I think I can draw some practical conclusions that have the potential to improve my running. These are my top 10 learning points:
1) Short time on stance is more efficient because there is less braking but very short time on stance increases the risk of injury because ground reaction forces are greater. So a very short time on stance makes sense for a sprinter but is more risky for a marathon runner.
2) Landing with the foot only a short distance in front of the centre of gravity (COG) minimizes braking and facilitates short time on stance
3) Holding the pelvis forwards facilitates landing a short distance in front of the COG.
4) High cadence is more efficient because the amount of energy wasted in compensating for free fall under the influence of gravity is less when the distance is covered in a large number of smaller strides compared with fewer long strides – but beyond a certain point, high cadence becomes inefficient; probably the limit is determined by the optimum speed of the ratcheting interaction between the muscle proteins actin and myosin. The question of whether or not this limit is fixed by your genes or alternatively might be improved with training is uncertain.
5) Landing with a rigidly extended knee increases risk of injury but landing with a very soft knee (low tension in quads) prevents a brisk recovery of impact energy via elastic recoil. When speed is the highest priority, a fairly high degree of tension in quads is best. In longer races, less tension in the quads might be safer, but too little tension will result in wasted energy.
6) The optimum point of contact between foot and ground at footfall depends on speed, and should be further forward under the ball of the foot at higher speeds. Except when sprinting, it is highly desirable to allow the heel to drop to the ground during stance to minimize risk of injury to the Achilles tendon and calf muscles
7) Some of the benefits of training, such as strengthening of bones and connective tissues accumulate slowly over a period of many months or years; training at fast speed before building up the required strength creates high risk of injury.
8 ) Running requires a moderate degree of development of many muscle groups. The muscular functions that are especially important to develop are:
· ability of the quads and calf muscles to capture impact energy at foot fall. This requires eccentric contraction.
· ability of the hamstrings to arrest the forward motion of the swinging leg in late swing phase to as to allow the foot to fall only a little in front of the COG. This also requires an eccentric contraction.
· strength of the hip abductors (eg glutes) to prevent the pelvis tilting to the unsupported side during stance.
· Strength of the trunk muscles to allow a relaxed carriage of the pelvis in a forwards position.
9) There is some evidence to suggest that running produces cumulative damage to muscles even in the absence of overt injury, so it is probably best to have mixed program that includes cross training.
10) There is unlikely to be one running style that is best for all purposes. It is necessary to make choices and seek a balance that best meets one’s priorities Perhaps the best illustrations of this are provided by the requirement of short time on stance and relatively high tension in quads at footfall when running fast, but due to the risk of injury, a somewhat longer time on stance and less tension in quads is preferable when running long distances.