Your most efficient stride length is determined by what feels most comfortable to you. You cannot run faster by consciously trying to increase your stride length. When you run, your foot hits the ground with great force. The tendons in your legs absorb some of this energy and then contract forcibly after your heel hits the ground, so you regain about 60 to 75 percent of that stored energy. When you try to take a stride that is longer than your natural one, you lose a great deal of this stored energy, tire much earlier and move your legs at a slower rate.
The only effective way to increase your stride length is to strengthen your muscles. The key to running faster is to make your leg muscles contract with greater force so they drive you forward with a longer natural stride. Competitive runners strengthen their legs so they have longer natural strides by:
• doing interval training (running very fast short bursts in practice two or three times a week)
• running up and down hills once or twice a week
Stress and Recover
You do not strengthen your leg muscles by running slowly. To make a muscle stronger, you have to damage the muscle fibers so they will be stronger when they heal. Competitive runners train by running very fast on one day, feeling sore on the next day, and then running at a slower pace on as many days as it takes for the soreness to go away. If you run fast when your muscles feel sore, you are likely to injure yourself.
You can also strengthen your legs by using special strength training machines. On the days that you run fast, you can do leg presses and knee and hip extensions. However, most runners are better off not using strength machines on their legs because running very fast damages muscles and so does using strength machines. The combined load of running fast and using machines increases your risk for major injuries.
Decreasing Stride Length May Reduce Injuries
A video at the New York City Marathon showed that the top 150 runners had the same cadence, taking 92 to 94 steps a minute. The difference between the top runners and the others was that the best runners took longer strides naturally. However, competitive distance runners suffer long-term overuse injuries more often than football players do because of the damage caused by the force of your foot hitting the ground during running. Running at six-minutes-per-mile pace, your foot hits the ground with a force equal to three times your body weight. This force in transmitted up your legs to your hips and back, and done repetitively can shatter bones and tear muscles and tendons.
Shortening your stride reduces impact forces and helps to prevent running injuries (International Sport Med Journal, Jan 2006;7(2):98 – 108). Researchers found that non-competitive runners who shortened their strides by increasing stride frequency by 5-10 percent:
• bounced less and landed closer to their center of gravity,
• had less force of foot-strike on their knees and hips and less bending of their knees and hips, and
• had less perceived exertion (Med Sci Sports Exerc, Feb 2011;43(2):296–302).
Problems from Running Shoes
Padded running shoes may actually increase your chances of injuring yourself. They cushion the force of your heel hitting the ground, so you may try to extend the length of your stride, land on your heels and hit the ground with much more force. When you take shorter strides, you are far more likely to land on the front part of your foot with much less force, which can reduce your chances of injuring yourself (Med. Sci. Sports Exerc, 2012;44(7):1325–1334). Data showing that people who land on the front part of their feet are injured less often led to a fad for barefoot running and for new styles of unpadded running shoes. However, it is incidental that a shortened stride causes you to land further forward on your feet; it is the decreased impact of the shortened stride that helps to prevent injuries.
Intervals for the Non-Competitive Runner
To become stronger and faster, athletes use a technique called interval training, in which they exercise very intensely, rest and then alternate intense bursts of exercise and rest until their muscles start to feel heavy. Intervals can be long or short.
• Long intervals take two minutes or more and are very tiring.
• Short intervals take less than 30 seconds and do not build up significant amounts of lactic acid in the bloodstream, so you can do lots of repeat short intervals in a single workout. There is no reason for a non-competitive runner to do intervals lasting more than 30 seconds.
Warm up by running slowly for 5-10 minutes. Then pick up the pace for about 10 seconds, and then slow down. When your legs feel fresh and you are not short of breath, do your next 10-second interval. Alternate picking up the pace and slowing down until your legs start to feel tight, and then cool down by jogging slowly for a few minutes.
If you feel pain in one area that does not go away immediately after you slow down, you should quit your interval workout for that day. On the next day or days, your muscles may feel sore, so you just jog slowly. When your muscles feel fresh again, take your next interval workout. As you get stronger, you can increase your interval duration from 10 seconds up to no more than 30 seconds.
If you are a regular runner, realize that you can become stronger and faster, and gain more health benefits, if you try to pick up the pace during your runs. However, this can increase your chances of injuries. You can protect yourself from injuries by:
• stopping a workout immediately if you feel localized pain that does not go away as soon as you slow down
• taking shorter strides
• avoiding running fast on consecutive days