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Running Research News And Events
November 05, 2009
Running With Style—Part I: Improving Technique for Better Running Efficiency
There’s little that coaches and exercise scientists haven’t examined in their never-ending quest to improve human performance. Two such hot and controversial topics, which have received a lot of attention over the past decade, are running technique/efficiency and running economy.
Coaches have had runners perform seemingly endless drills for many years in an effort to improve technique without any good reason as to why runners should perform these drills. It’s been more a matter of intuitive reasoning coupled with trial and error experimentation, i.e., “it seems like it should improve their running style and make them run faster”.
Contrary to this intuitive reasoning, Krahenbuhl et al. (1997) found that emphasizing “proper” running technique (arm movements and body alignment) did little to enhance running economy in short-term training programs. But behind the scenes, in the biomechanists and exercise physiology labs, scientists have been quietly going about their business and have now amassed a large volume of research to point runners in the right direction for maximizing their running technique and economy.
What is Running Efficiency?
Current research indicates two ways to improve our running—through technique modification or by adding additional training of some type. The first, technique modification, is called running efficiency. A runner with good mechanical efficiency exerts greater force and power for the same amount of energy than a runner with poorer efficiency. Efficiency is all about examining the biomechanical structure of the running body and its relationship to how it functions.
By understanding how the structural units of the body (such as muscles, bones, tendons) work when we run, biomechanics can determine better ways to improve performance. For example, breaking down the sequence of the running action into sub-components and then working on these individual movement sequences help runners move more efficiently. Some major aspects of running efficiency currently being examined are running technique and style, stride frequency and cadence, stride length, and breathing rate.
What is Running Economy?
The second way to improve our running movement is through better running economy, which like efficiency is the sum of the influences of many variables. Exercise scientists look closely at everything from the oxygen cost of running and pulmonary ventilation, to muscle fiber typing and how strength and flexibility affect running economy—the results of which will surprise you. A runner with good movement economy consumes less oxygen at a given running speed. For example, given two runners with identical VO2 max figures, the runner who can race at a faster pace (exerting greater force) while processing the same amount of oxygen will ultimately win.
The fact is, running economy and efficiency are closely related. A runner’s biomechanics and efficiency are one of the chief determinants of running economy. It’s highly likely that a runner with a smooth, efficient running technique will have excellent running economy, especially at the elite level. For example, there are very few ugly ducklings in Olympic distance finals these days.
One only has to watch Ethiopian Kenenisa Bekele flowing effortlessly, yet powerfully, around the track, averaging 61-second laps for 10,000-meters, to see a superb combination of running efficiency and economy. The big difference between running efficiency and running economy is that an efficient running technique boils down to higher mechanical power output per unit of energy, while economy is measured by oxygen consumption for movement velocity at a given speed—quite simple really!
The first part of this two part series considers all things biomechanical. In other words, running efficiency and how to improve running efficiency. Part two (Jan/Feb 2009 issue) explores running economy and techniques to improve running economy.
Advantages of Improving Running Efficiency
What then are the benefits of improving the mechanics in running technique, and thus our running efficiency? A runner with good biomechanical efficiency will run farther and faster per unit energy expended than someone with poor efficiency. Or another way of saying it is, … will use less energy to do the same work (driving across the ground) than a less efficient runner. Thus the efficient runner goes faster or maintains a high cruising speed for longer.
The question remains, can we improve our running technique? Here’s what some running coaches say about this often-debated topic:
Brown and Graham (1983), in their book Target 26, claim that “… as a general rule, reasonably smooth and efficient running form evolves after many months and miles on the roads. Because each of us is structurally different, you would expect variation in individual styles. ... you are probably better off not changing your style”.
Daws (1985), in his book Running Your Best, says running technique “… is an individual matter. Over the course of years of running it becomes natural, or well established. Changing it disturbs the runner’s balance”. However, Daws concedes it may be necessary to change idiosyncrasies of running style if the current style actually inhibits performance.
Glover and Florence Glover (1999), in their book The Competitive Runners Handbook, claim that technique is the most ignored ingredient in successful racing. However they mention, “… some runners have form quirks that apparently offset musculoskeletal asymmetries naturally, and shouldn’t be changed”.
Galloway (1986), in Galloway’s Book on Running, believes “ … there is no single prescription for efficient running, for we are all put together differently. Never force a particular running style on yourself that doesn’t feel right”.
The generally consensus among these coaches is that one should not tinker with one’s running style unless it is inefficient. Most coaches know the frustration of working on a runner’s form to the point where it looks pretty good, only to have the runner revert back to his old ungainly style when fatigued from hard training, or in the middle of a race.
Running Efficiency—Changing Running Technique
Is it possible to change a runner’s style to improve efficiency? For every study that finds no improvement in running performance with attempts to improve technique (see Box 1), there are other studies, such as Cureton et al. 1997 and Joyner 1993 demonstrating that training adjustments to improve the efficiency of children’s and adult’s activities can happen and does improve exercise performance.
Running technique just happens to be a difficult proposition to change because, in many cases, the apparent inefficient movements that some runners exhibit may actually be counterbalancing a structural deficiency elsewhere in the body. However, improving running technique can be done! A recent study by Fletcher et al. (2008) on the Pose ® technique created quite a stir among biomechanists and coaches.
With the Pose ® technique, the runner balances his/her body weight vertically by aligning the shoulder, hip and ankle over the support leg with the foot strike impacting on the ball of the foot, instead of the standard heel-toe movement. Although the Pose ® technique runners improved their post-test 2,400-meter time by an average of 24.7 seconds, compared to a meager 3 second decrease in a heel-toe strike group of runners, the Pose ® runner’s improvement was not statistically significant. Despite this, I know plenty of runners who’d give anything to improve their 3K running time by 25 seconds! Nevertheless, runners should be cautious about making wholesale changes in running technique.
Box 1. Studies concluding little or no improvement in performance from modifying running style
There also maybe a correlation between running efficiency and speed. Costill (1986) mentions in his book that the faster the running pace, the less efficient the runner’s movement. Film analyses has revealed that middle distance and sprint runners, at running speeds of 7-12 mph, have significantly higher vertical oscillation movement when compared to marathoners. Exaggerated up and down bouncing vertical movement is unfavorable to the economy of the long distance runner because our energy is best transferred into horizontal movement instead of upward movement.
Increasing Running Efficiency through Stride Length and Stride Frequency
Biomechanists will tell you that there are three ways one can increase running speed:
Ø increase the number of steps per minute (stride frequency or turnover)
Ø increase the distance of each stride
Ø increase both simultaneously
Research on these topics started in 1944 when a Danish study (Hogberg 1952) looked at the stride patterns of their 5K and 10K champion. When running speed increased from 9.3 km/hour (5.8 mph) to 17.8 km/hour (11 mph), stride frequency increased only by about 10% but stride length increased a whopping 83%. Once the runner exceeded 23 km/hour (14.3 mph) however, speed increased due to increased stride frequency, also known as leg turnover. Part I: Improving Technique for Better Running Efficiency
The take home message is distance runners are better off concentrating on increasing stride length, and sprinters are better off increasing both leg turnover and stride length. As a general rule, increased stride length should increase distance-running speed.
Only at faster speeds, such as the final sprint at the end of a race, does stride frequency become a factor (see Box 2 for increasing stride frequency). Thus a prudent distance coach will give his athletes drills aimed at lengthening stride, but still throw in the occasional fast leg turnover drill to ensure they are not left behind in the home straight.
Box 2. How can we increase stride frequency?
How much should we increase our stride length?
Each runner will have an optimum combination of stride length and stride frequency, and it depends on the individual’s mechanics. But avoid over-striding, because the foot lands in front of the body’s center of gravity creating a braking motion.
Too short a stride and we consume too much oxygen because we’re inefficient at that pace. McArdle et al. (2007), in their textbook Exercise Physiology, suggested that, “… well-trained runners should run at the stride length they have selected through years of running”. They claim that, “… biomechanical analysis may help the athlete correct minor irregularities in movement patterns while running. For the competitive runner, any minor improvement in movement economy generally improves performance”. Part I: Improving Technique for Better Running Efficiency
The important thing to remember is that each runner establishes her/his best cruising speed and stride length where oxygen consumption is the lowest. This is best measured on a treadmill with a metabolic cart analyzing oxygen consumption at varying paces. Another interesting technique to modify stride length was used by Morgan et al. (1994).
They used the intervention of a short-term audiovisual feedback program focusing on optimizing stride length for runners with uneconomical stride length patterns, and found that runners benefited from this feedback. However neither of these techniques are practical for most of us. So we can do the next best thing, run at varying speeds on a flat 400-meter track and note the pace where you subjectively seem to cruise at a nice fast steady state.
We tend to self-select an optimum pace and stride length for ourselves. Then, for example, we can train to increase the optimal pace through interval sessions.
While we’re discussing stride length, an interesting but related tangent is a study by Esteve-Lanao et al. (2008) who examined the loss of stride length with fatigue. They found that periodized strength training (see Running Research News volume 24 issue 6, August 2008) reduced the loss of stride length during endurance running—a decided advantage for marathoners who try to maintain their form towards the end of the 26.2-mile event. Loss of form can add minutes to a runner’s time. Part I: Improving Technique for Better Running Efficiency
Here are some figures on stride length at various speeds.
Box 3. Interesting factoids related to running efficiency and force
Breathing Rate and Pattern
Daniels (2005), in his book Daniel’s Running Formula, describes the importance of being aware of your breathing pattern while running as a useful tool when gauging training and racing pace. Most elite runners breathe with a 2-2 rhythm; that is two steps (one with right and one with left foot) while breathing in, and two steps while breathing out. Most good runners take about 180 steps per minute, giving them about 45 breaths per minute. During particularly hard racing, runners might breathe with a 1-2 rhythm, and when running slowly breathe at a 3-3 rate. Breathing rates can be used to monitor your pace during a race. Running up hills for instance, you can try to maintain a 2-2 rhythm, to ensure you’re maintaining a constant intensity and not getting into an anaerobic zone.
Other Biomechanical Factors
In addition to the above, many other biomechanical factors have been examined for efficacy in improving running efficiency—more than can be detailed here. They include: average or slightly smaller than average height for men, slightly greater than average height for women, ectomorphic (thin) stature, low percentage body fat, narrow pelvis and smaller than average feet, gait patterns, effective exploitation of stored elastic energy, lightweight well-cushioned shoes, breathing/stride rate, among many others. These profiles will be examined in a future article.
Clearly, improving running technique is a complex process. How might we go about improving our running technique and efficiency? Here’s a handy checklist for you to use. Part I: Improving Technique for Better Running Efficiency
Technique Advice and Checklist Dos and Don’ts
Don’t . . . .
Do . . .
November 03, 2009
VP TRAINING—JUST RIGHT FOR MARATHONS AND 5KS
A little-known type of training—VP effort—is great for improving marathon and 5-K performance capacities. VP workouts differ from traditional interval sessions because they allow no easy, jogging recoveries. Instead, marathon and 5-K paces are alternated over running segments which may last for up to 2400 meters or more.
At this time of the year, marathon runners are looking for the perfect “tune-up” workouts for their marathons–sessions which spike fitness and increase the likelihood that an upcoming marathon can be completed at goal speed.
5-K runners, on the other hand, are searching for sessions which will produce one last 5-K PR before the season ends.
Strangely enough, both groups of runners can employ the same kind of training – in the form of VP workouts. Performed properly, VP (variable-pace) sessions produce major upswings in aerobic capacity, vVO2max, and lactate threshold, all of which are important for 5-K and marathon success. VP training also enhances running economy at both 5-K and marathon
speeds, making goal pace for either race more sustainable.
VP running is very similar to traditional interval training, but it differs from classic interval work in a fundamental way: When you conduct intervals, you ordinarily alternate between a high-quality velocity (your work-interval speed) and a rather-low quality pace (your recovery, jogging speed). In VP training, you interchange two very important, high quality running speeds during the course of your workout.
How is a VP workout actually constructed?
After your short furlough, run 1600 meters while utilizing the same pattern (400 meters at 5-K pace, 400 meters at marathon tempo, etc.). Jog easily again for three to four minutes, and then complete one more 400-400-400-400 ensemble before cooling down. You will have completed 3 X 1600, with 2400 meters total at 5-K pace and 2400 meters at marathon speed. For subsequent
VP training, you may add an additional (fourth) 1600 (provided all went well with 3 X 1600). If you are an advanced runner, you may work up to 5-6 X 1600 in a reasonable fashion. Note that your average pace for the 1600s will be in-between 10-K and half-marathon speed.
Let’s say, for the sake of argument, that you run your 5Ks at a tempo of 6:12 per mile. Remember that your pace slows down by roughly four seconds per 400 meters every time you double your race distance (from Horwill’s Law of Running). Thus, your 10-K tempo would be 6:28, your half-marathon pace would be 6:44, and your marathon alacrity would be about 7:00. Within your VP 1600s, 800 meters would be completed at 6:12 tempo and 800 would be knocked off at 7:00. Thus, your average pace would be 6:36 –halfway between 10-K (6:28) and half-marathon (6:44) speeds.Of course, if you are a 5-K runner you might be saying: Wait
a minute – how can such tepid, below-10-K-velocity running boost my 5-K chances?
That’s a logical question, but you should not be worried. Bear in mind that each 1600 within a VP session features 800 meters right at current or goal 5-K speed. Thus, half of all the running you conduct within a VP is right on target, undertaken at a very high intensity (5-K speed generally corresponds with ~ 95 percent of VO2max). Note, too, that 400s at 5-K pace take on a
different quality when they are conducted immediately after 400s at marathon tempo, instead of being undertaken after inchmeal, jogrecovery intervals. The intensity of marathon 400s is high enough so that 5-K-paced 400s will be completed at higher fractions of VO2max, at higher percentages of maximum heart rate, and with higher levels of blood lactate, compared with a situation in which easier recoveries are utilized.
And that leads to another great progression possibility with VP. If you are a 5-K runner and your initial VP session goes well, you can throw away the 1600s and utilize 2000-meter segments. Within each 2000 meters of running, the first, third, and fifth 400s
would be at 5-K pace, the second and fourth at marathon tempo. This would provide you with two opportunities (within each segment of the VP) to challenge yourself with 5-K running without significant recovery, instead of the usual one (that is, the third and fifth 400s of a 2000-meter segment would be uniquely challenging, in contrast with just the third 400 of a 1600-meter jaunt).
When you change over from 1600- to 2000-meter segments, it is reasonable to begin with 2 X 2000 and then “graduate” to 3 X 2000 at a later date (advanced runners may earn their VP Ph. D. by moving up to 4-5 X 2000).
Runners who are primarily interested in the marathon will find VP training to be particularly tasty, since it constantly forces them to find and sustain marathon pace in the face of fatigue induced by 5-K-tempo running. In addition, the spike of intensity added to training by the inclusion of the 5-Kpaced 400s will boost fitness to a greater extent, compared with similar amounts of running at marathon tempo only. One very cool progression for the marathon runner is to move to 2400-meter segments: With 2400s, a marathoner must dial up marathon speed three times per segment, each time after a relatively scalding 5-K burst (of course,
with 1600- or 2000-meter segments, this must be done just twice). The marathoner may start with 2 X 2400 and move up to 3 X 2400 (advanced individuals will progress to 4 X 2400).
Note that VP work represents terrific pace judgment training; after a few VPs, 5-K and marathon runners develop a great “feel” for their paces in the respective races. VP effort also enhances running economy at both 5-K and marathon velocities, and a VP session
is exactly the kind of work out a marathoner can conduct about a week in advance of a marathon, when he/she is searching for a workout which will both advance fitness and develop additional ease and confidence at marathon tempo. For many marathoners, a VP session
of 3-4 X 1600 would be just right when conducted about seven days in advance of the big day (to obtain more information about how to train during the last month before a m a r a t h o n , pl e ase g o t o h t t p : / /w w w . r u n n i n g r e s e a r c h n e w s . c o m /b a c k i s s u e D e t a i l s . p h p ?x=xYE6k2j054jfdX1m6DQxschwGgXrMDhiHgKoHWq66ko%3D
Figuring your 5-K and marathon paces for your VP workout is fairly easy. For the shorter distance tempo, take a recent, typical 5-K time, convert it into seconds, and divide by 12.5. The result will be the time (in seconds) you should take to complete each 5-K-based 400 within your VP.
For example, if you run the 5K in 19 minutes, 19 X 60 = 1140 seconds, and 1140 divided by 12.5 = 91 seconds per 400. You can also utilize a goal 5-K time or pace, which will ordinarily be two to four seconds per 400 faster than your current 5-K capability.
For the marathon, take your expected time in the race, convert it into seconds, and divide this rather-large number by 105.5 to obtain the time you should take to run each marathon-paced 400 within your VP. Of course, your expected pace for the marathon should be reasonable, based on previous marathons or on Horwill’s-Law conversions from your recent performances in shorter races. We can’t forget about 10-K runners, who can also profit greatly from VP training. Running the 5-K-paced intervals of the VP without significant recovery will make 10-K speed feel easier, and it will allow 10-K runners to include faster segments within their 10-K competitions.
We cannot close this article without including the “Finnish formula” for VP training. VP work is popular in Finland (1), and many serious Finns like to conduct a VP workout with just one set of gradually expanding length. In other words, they will – over time – gradually increase the number of 400s in the first set to six, eight, 10, 12, 14, etc., until the workout eventually consists of continuous running with no three- to four-minute breaks (there is no second set).
The VP workout simply ends when fatigue makes it impossible to maintain the desired pace(s). Some experienced harriers have gradually worked their way up to 24 400s without stopping (12 at each important pace), and this is almost like running at 15-K race pace for six miles.
VP training is very specific to the 5K and marathon, and it can do wonders for your aerobic capacity, lactate threshold, running economy, pace judgment, stamina, and confidence. Carrying out VP training is challenging and fun, and VP provides a welcome break from conventional
interval training. Best of all, when it is part of a carefully constructed program, VP training will help you achieve significant improvements in performance.© VP TRAINING—JUST RIGHT FOR MARATHONS AND 5KS