|
|
by David Hampson
Assuming you have somehow achieved a lofty VO2 max and pushed your lactate threshold as high as possible, the best way to get your body to run faster with less effort is to improve your running economy, the oxygen cost of running at any particular pace. As you become more economical and require less oxygen to run at a given running speed, all sub-maximal running paces will feel easier because the heart won't have to pump as much blood to the muscles and you will be further away from your VO2 max (maximal oxygen consumption). By maximizing your economy, you will be able to compete with other runners who have higher VO2 max values, but are inefficient. If they are working at a greater percentage of their VO2 max due to wasteful oxygen consumption, they will also be working at a higher heart rate and building up more lactic acid than the efficient runner with an equal or slightly lower VO2 max.
Unfortunately, the difficulty with enhancing running economy is that there is no proven method of improving your form to run more efficiently. In fact, one of the worst ways to improve economy is to change your style in an attempt to mimic the "ideal" form. This was attempted in a biomechanics study at Wake Forest University, and the results indicated that the runners' economy was unchanged after five weeks of modifications. The problem in developing a prototype for an ideal running form is that everyone differs in their body structure, and thus in the biomechanics necessary to be an efficient runner. Some runners who look awkward when they run and seem to be "all over the place" are in fact quite economical, while other runners who look "smooth as silk" may be below average in running economy. Joan Benoit Samuelson, the American record holder in the marathon, is a classic example of a runner who looks smooth, yet has tested below average in running economy.
Then is all hope of improving economy lost? Isn't there anything we can do to become more efficient runners? Fortunately, the answer is yes; while exercise scientists can't describe an ideal running form to mimic, there are several strategies we can use that are likely to improve our economy. Generally, runners tend to become more economical as they gain experience and log more cumulative miles. Regular doses of speedwork at race pace or slightly faster will naturally improve economy at faster speeds. That explains why runners feel "uncoordinated" and "awkward" when attempting to run at race pace after a prolonged period of exclusively distance training. You can avoid this from happening by keeping some fast running in your training throughout the year. This does not have to take the form of intense or structured speedwork. During a base-building cycle or active recovery period from a hard racing season, all you need to do to preserve race-pace economy is to complete a set of 8 to 12 strides after most of your distance runs. Strides are semi-sprints in which you gradually build up to full speed over the course of 100 to 150 meters. The key is to run them fast, but relaxed. If you are straining or tie up in the middle, you are working too hard.
In addition to mileage and speedwork (things most runners do anyway), there are several conscious form adjustments we can make that are applicable to most runners. The first has to do with stride rate versus length. When it comes to running faster, there are really only two ways to increase speed: taking longer strides or achieving quicker leg turnover. Although both increase as we run faster, stride length tends to increase more than stride frequency. How do you know if you are taking the right stride length for a given running pace? Fortunately, most runners subconsciously take the stride length that is most efficient for the pace they are running and their individual biomechanics. Thus, runners should not try to artificially increase stride length in an attempt to run faster. Overstriding can cause the foot to land in front of the body's center of gravity, which would then serve as a braking force to forward movement. However, you can increase your natural stride length by increasing leg muscle strength, which yields greater propulsive thrust. Regular hill work and resistance training are the best way gain the strength necessary to increase your leg power and natural stride length. There is some evidence that wearing a weighted running vest can be beneficial in this respect, though I would exercise caution if you decide to try one. The increased weight may strengthen muscles, but it also places a great deal of extra stress on the tendons and ligaments.
On the other hand, there does seem to be a range of optimal stride rates applicable to most runners. Observational research indicates that elite runners in distance events (800m to marathon) strike the ground with 180-200 steps per minute. Check your stride rate the next time you run by counting how many footfalls you take in one minute. If your rate is currently less than 180, you may benefit by making a conscious effort to increase your cadence.
A second conscious form adjustment we can make relates to the positioning of the torso. The upper body should be almost erect, with minimal forward lean. Seldom do people run with too much backward lean; the problem is almost always the opposite. Excessive forward lean of the torso places strain on the back muscles and can cause the upper body to work harder in maintaining balance. The best way to check this is to have someone observe you as you run. I have found that glancing at a large store window as I run by is also an effective way to analyze upper body lean. If you find that you run with too much forward lean, a program of abdominal strengthening exercises often helps correct the problem in conjunction with a conscious effort to run more upright.
One additional thing we can do to influence running economy is psychological in nature. Research has shown that running economy is adversely affected by psychological tension. Tense runners use more oxygen than normal to maintain their pace because too many muscles are contracted that don't contribute to, and may impair, faster running.
This fact is particularly applicable to important races, when nervousness may cause you to run less economically. Practice relaxation techniques regularly and it will be easier to relax on race day. There are many excellent books that can be purchased on sports psychology if you are interested in learning how to effectively utilize relaxation techniques and visualization for improved performance.
In summary, running economy is an important training element, one that should not be overlooked when planning a running program. It is a performance factor most runners can continue to improve, even after years of training. After you have developed an adequate mileage base, adding speedwork and strength training, making the conscious form adjustments discussed above will result in an outcome we runners all strive for-running faster and easier!
David Hampson is currently a student at Wake Forest University in North Carolina pursuing a degree in exercise science. His permanent residence is in Exeter, New Hampshire. He aspires to obtaining a doctorate in exercise physiology and possibly pursuing research in that field. He is an accomplished distance runner, competing in cross country and track for Wake Forest. His PR's include 15:35 for 5 km, 32:35 for 10 km, and 54:57 for 10 miles.
David's e-mail address is: hampdb00@wfu.edu. He encourages feedback on his articles.
© Cool
Sports 1998