To improve speed you need to increase stride length and/or strike rate or stride frequency. If you only focus on one of these then the other will suffer and so will your speed. The two need to be balanced to get the optimum results, but how balanced, is very much dependent on the individual.
For more information see Speed, Interval and Fartlek Training Explained.
The length of your stride is the one that’s optimum to you. As it is, most beginner runners over stride and land hard on their heels. If you practice shortening your stride so your foot strikes beneath your hips you’ll run more efficiently. The goal is to decrease the foot contact time with the ground makes and run so your legs turnover smooth, turning like the pedals on a bike.
Click here for information on Beginners Running: Five Common Mistakes.
With a quicker or more frequent stride rate you will increase the power in the leg muscles and this in turn will increase your stride length. Jack Daniels, author of Daniels’ Running Formula recommends training like elites, at 180 steps per minute to find your optimal stride length. (Count for 90 on one foot and multiply by two).
Elite runners who appear to have a shorter stride, will in fact have a long stride, run next to one, and you’ll see it’s like running alongside a gazelle. To get that effortless appearance and faster running action you need to work on improving both stride length and frequency together.
An interesting article by blogger, runner, sports scientist, Steve Magness on his site www.scienceofrunning.com discusses two studies of elite athletes that confirmed how different combinations work for different runners. He cites one study from the 2007 10k world championships which included Bekele (first), Sihine (second) and Mathathi (third). The study found that the three runners adopted different techniques. Bekele for example had a low stride frequency and long stride length for the first 9k, but in the last stretch he upped his frequency and his stride shortened. The reverse was true for the other two. Magness explains that other studies have found that ideally switching between the two is optimum and that elites often run using the weaker approach for the last bit of the race, when they’re tired, having run strong for the majority of the race (ie either with a longer stride, or quicker turnover).
How to improve your stride
For more information see TRX Suspension Training for Runners
For more information see Strength Training for Runners
For more information see Hill Training Explained
For more information see Speed Training Explained
What Next? To improve as a runner your training schedule must be varied; don't fall into the trap of running lots of junk miles. Free running training schedules.