RUNNING FASTER. INCREASE STRIDE LENGTH OR FREQUENCY?
Report #6170 4/11/94
If you want to run very fast in races, you have to run very fast in training and use weights or weight-training machines two or three times a week. How fast you run depends on two factors: the length of your stride (stride length) and how fast you move your legs (cadence). In one study, the top 70 runners averaged 90 to 96 strides per minute during the New York Marathon. The difference was that the faster runners took longer strides. However, consciously trying to take longer strides causes you to move your legs at a much slower rate and actually slows you down. Strengthening your legs so you can take longer strides naturally helps you to run faster.
You strengthen your leg muscles by running very fast and by exercising them against increasing resistance. Just exercise does not make muscles stronger. The faster you run, the harder you push against the ground and the stronger your legs become. However, each time that you run fast, your leg muscles are injured and feel sore on the next day. If you run fast when your muscles feel sore, you are likely to injure yourself. Runners train by running very fast on one day and then running at a slower pace on the next days, until their muscles stop feeling sore. 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. Recent research shows that you should also train for strength by rotating your body against increasing resistance on a special rotational strength training machine.
By Gabe Mirkin, M.D., for CBS Radio News