Jim2's Running Page

Stride Mechanics - Post 1

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7/16/98 

There is a thread farther up the page that Jimmy initiated and I want to comment on. I thought I would do it as a new post because the chances are greater that it won't get lost in the rapid rate at which this Forum grows. And I think it's important that a few people read it.

You make some good points, Jimmy. And everyone here who is trying to advance their running should benefit from them. But, they should be used selectively and carefully. I would like to offer a few thoughts and observations, gleaned largely from Bob Glover's "The New Competitive Runner's Handbook", Jack Daniels' "Running Formula", and my personal experience.

There are only three ways to increase speed.....increase stride length, increase stride rate, or increase both. Which is more important in running faster depends on the individual runner, the type and distance of racing one is going to do, and how susceptible to injury the individual is.

Most elite runners do have a stride rate of 180 steps per minute or greater. However, studies have shown that average runners have a stride rate of only about 9-10 steps per minute slower. Thus, although there is some room for an average runner to increase stride rate, it's limited (only about 5%.) Beginners often have more room to improve stride rate since they may be in the 150-160 steps per minute range, or even lower. Basically, however, once you have reached the "average" level (let's define that as "mid-pack" in a race), greater results can be achieved from increasing stride length.....which is the bigger factor separating elite and average runners in a race.

Foot strike is a factor that enters into how much an individual can increase either stride rate or length. A ball-heel strider can increase both stride rate and length. A heel-ball strider is limited in how much stride length can be increased, because of the dynamics and bio-mechanics involved in heel-ball striking, and has to rely more on stride rate gains. However, ball-heel striders expend more energy per stride. Also, the ball-heel stride has an increased susceptibility to injury, since it doesn't permit the shock absorption of pronation as much as the heel-ball stride does. Most people are natural heel-ball striders. Few are natural ball-heel striders.

There is nothing wrong with a heel-ball stride if done properly. The heel strike should be "light." The outside of the heel should very gently touch the ground slightly forward of a runner's center of gravity and you should flow smoothly through the stride as if you are rolling over the ground to a pushoff from the big toe. It's almost a mid-foot strike, but not quite. It is not true that "heel striking" necessarily produces greater "shock" or "compression" and increased injury risk. Just the opposite. Heel strike enables pronation, which is one of the body's natural shock absorption techniques. Ball-heel striding produces minimal pronation. If you land with a heavy heel strike followed by your foot slapping the ground, you are overstriding, which results in the braking action that you described and does increase susceptibility to injury from "pounding." Although the ball-heel stride offers the greater speed potential, the heel-ball stride is the more efficient, can be maintained longer when racing, and minimizes the risk of injury.

Glover recommends that beginning runners and racers, as well as all marathoners, use the heel-ball stride for maximum running efficiency and injury prevention. He points out that even competitive runners often train with a heel-ball stride and use ball-heel for speed work and racing, but not for marathons. He recommends not using the ball-heel stride until you can run 6-7 minutes per mile or faster, which will put you at mid-pack or better in most races. At this speed, you will naturally drift more to midfoot and ball-heel striding anyway. You don't get to those speeds without the longer stride that midfoot striding enables. However, slower runners place significantly increased stress on shins and achilles tendons with the ball-heel stride.

Glover defines two types of runners. The Shuffler and the Power Runner. The Shuffler runs with feet low to the ground, little knee lift and mostly a heel-ball foot strike. The shuffle is not a derogatory term, in this sense. It's a highly efficient form of running with few extraneous motions to waste energy. Power Runners use the ball-heel stride and a longer stride. The longer stride comes from pushing off strongly with the trailing, or support, leg and thrusting the knee (but not the foot) of the leading leg forward. The power stride requires well developed quadriceps and more energy than the shuffle because the longer stride comes from a strong leg "drive", which is inefficient for a long distance runner. It's also interesting to note that, even with a ball-heel stride, a power runner can overstride, if s/he isn't careful.....and with even more negative consequences than overstriding by a shuffler. Not only is there a braking action caused by overstriding, but because of the lack of a forward "rolling" motion of the foot that a shuffler has, the power runner now has to pull his body through the stride.

Sprinters are power runners. Most elite and some advanced runners power run at shorter race distances. However, few marathoners of any level use the power running method. Glover points out that many elite runners, such as Derek Clayton, Alberto Salazar (two previous marathon world record holders) and RW's own Amby Burfoot had to learn to shuffle when they moved up to the marathon distance. Power running simply requires to much energy for even most elite runners to maintain over the marathon distance.

My points in all of this are:

1) Most of the people on this Forum are relative beginners and probably should not attempt ball-heel striding, unless it's their natural stride, until they are more developed and experienced. The increased risk of injury is too great. Advance to at least a mid-pack level runner before experimenting with it.

2) Anyone planning to run a marathon should stick to the shuffle method of running, which mandates a heel-ball stride.

3) There is nothing wrong with anyone attempting to increase stride rate or stride length. In fact, it's the only way any of us become faster runners. But, dramatic changes to one's natural running style to do so can have negative consequences. So, be careful.

4) The way to increase stride rate and/or length is to work on them during speed workouts, which shouldn't be more than 15% of one's weekly mileage. That's one of the reasons for doing speedwork. Use these sessions to ease into the techniques you are going to use to get faster. Let your body adjust to and develop into the changes. Don't manipulate stride mechanics for the purpose of trying to make every training run dramatically faster than you have been running Doing so will make every run closer to a race effort and increase the risks of overtraining or injury. Continue to let your race pace drive your training paces as you deal with speed in speed workouts.

5) It's OK to sacrifice some stride length for increased stride rate on easy runs if you feel that increases your pace somewhat.....as long as you don't increase your level of effort as perceived or as measured effort with a HRM. Yes, this might permit you to run a little faster at a comfortable effort. But, be aware that you are also now "practicing" (developing??) a shortened stride length, which ultimately is the factor that separates the best you can be from second best. Personally, I would only do that if I was overstriding in the first place. Then you would be correcting a problem, which is what you are actually doing if it makes you faster without increased level of effort. After all, you are still moving the same body mass over the same distance, which takes a fixed amount of work. The ability to do it faster probably means that you have eliminated a braking action and are running with greater economy, i.e., you have corrected overstriding. Glover claims that studies have shown that the average runner overstrides. And, you can bet that most don't know it!

Remember, there aren't any silver bullets in running. But, there are 3 "P's" which are all important to making progress without undue injury risk......Patience, Perseverance and a Plan.

Jim2