Two main factors determine your running speed, your stride length and your stride frequency & you can increase running speed in three ways - Increase the length of your stride, increase stride frequency or do both.
Stride length is the distance between successive ground contacts of the feet, from heel to toe and itís measured in the distance thatís covered when the foot isnít touching the ground. increasing stride length will enable you to increase your speed. You can do this by hill training, speed work, and weight training, which will make your back leg stronger and give you more ability to push off. Many studies have shown that most runners tend to over-reach when they create their stride, meaning that quicker runners have shorter strides. Stride length will tend to be shorter on uphill runs and longer on downhill ones, but must remain under control.
Stride frequency is measured in the total number of times your feet touch the ground per minute, with running speed being determined by the stride length and frequency being multiplied together. If you want to run faster you also have to increase the frequency of your stride. Studies showed that the stride frequency of many of the best runners tended to be 9 steps per minute higher than others. Quicker strides are better to use then, but itís more important to have longer and more controlled strides. The faster runners usually held a steady rate throughout the race. It was found in a marathon that many runners begin to have deteriorating strides at the 30KM mark. Although it declines at points throughout, this is where the most noticeable gaps occurred.
Long Races (Marathon) & Beginners: Increase the frequency rather than length and use "Heel of the foot" strike on the first stages of the race. In "Heel of the foot" method, center of gravity is a bit behind the striking foot and If your reach out too far in front to increase stride length theyíll overstride and sacrifice power as a result. The longer your stride the more vertical bounce you have results in covering more distance and increase the impact stress of foot striking. It often involves straitening the knee and landing on the entire surface of the foot. This will result in transferring more of the shock throughout the entire leg and not just the foot itself. If you learn to increase your cadence gradually, you will naturally shorten your stride. We recommend above 80 right foot strikes per minute.
Shorter Races (10K & Half Marthon) & Experienced Runners: Moderately increase both frequency and length of your stride without overdoing it. It is recommended that you use "Ball of the foot" strike and lift your knees a bit higher to get more length. Also make sure you align your hips properly. If you allow your body to fall back too far itís placing your center of gravity is shifted backwards and you have to pull forward to compensate. by keeping the hips, which are the center of gravity, in front of your support leg, you can push onto the ground and give yourself more of a boost with your supporting leg, or back leg. The more drive into the ground, the easier you can push forward and are able to push hard into the ground with the support leg. The greater the drive into the ground, the greater the thrust forward. (*This stride does allow for more power and speed, but itís harder to maintain it over a long distance. Itís best use for shorter races and sprints. )