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 . . . .

• swing your arms sideways across the centerline of your chest
  



• have excessive head movement and rolling
  



• flap your wrists
  



• allow your elbows to cross forward past your torso
  



• have much vertical oscillation (upward movement)
  



• have side to side movement
  



• bring your knees up high in front of you
  

Do . . .

• start being aware of your technique and form while running
  



• move arms forward and backwards from the shoulders
  



• keep shoulders down, arms and face relaxed
  



• keep elbows at (about) a 90 degree bend
  



• carry your arms between your waistline and chest
  



• carry your hands forward near your chest with a short compact arm swing and back as far as the seams of your pants
  



• relax your wrists and hands
  



• push your chest forward slightly
  



• rotate your pelvis slightly forward
  



• keep trunk slightly forward, but maintain an upward body position
  



• keep your upper body forward over your feet
  



• have your foot strike the ground under the bent knee after the leg has begun to swing back under the body (not on its way out)
  



• land on your heels and roll through to the forefoot for take-off
  



• keep your center of gravity over your foot
  



• transfer your weight evenly from one foot to the other
  



• strive for optimal stride length
  



• occasional leg turnover workouts to increase stride frequency
  



• make sure your arms and legs are synchronized in the same rhythm
  



• when speeding up, drive more with your arms
  



• try to run with a rhythmic flow
  



• run with “light feet” and bounce quickly and lightly off the ground
  



• monitor your breathing pattern
  

 Part I: Improving Technique for Better Running Efficiency