For Inside Triathlon

Duathlon Column

April, 2000

Developing Speed Skills

©1999 Joe Friel

            It’s really quite simple. To run faster all you have to do is increase your leg turnover or lengthen your stride. In fact, running speed may be expressed as a formula using only these two variables:

Run speed = stride rate ´ stride length

            The same may be said for riding a bike fast, but now we use gear size instead of stride length:

Bike speed = stroke rate ´ gear size

            So to ride a bike fast, you can either turn the pedals around at a high rate, use a high gear, or do a little of both. That’s all there is to it.

Economy

Well, actually there’s more to it than just that. There are these other things called aerobic capacity (VO₂max), lactate threshold, and economy that make it possible to keep the cadence high, the stride long, and the gear high for a long time. Of these the most highly trainable for the fit athlete is economy.

Economy refers to how much oxygen is used when running or cycling. By improving your economy you can run and bike using a smaller percentage of your VO₂max, so it feels easier. Or, at the same effort, you can run and bike faster once economy improves.

Economy is mostly determined by biomechanics—how efficiently one moves the various body parts while biking and running. This is a nervous system function. It does not have anything to do with how great your aerobic capacity and lactate threshold are. Since economy has nothing to do with these aerobic and anaerobic functions, it requires a different way of thinking when it comes to training. Breathing hard does not improve the functioning of the nervous system. Nor does fatigue. When it comes to improving your economy you must avoid both of these common aspects training as they will prevent you from becoming more economical.

Improving biomechanics requires concentrating on making a few precise movement patterns and then taking a relatively long rest break before trying it again. After repeating this pattern several times, it’s best to call it a day before fatigue sets in and you get sloppy. If you’ve ever tried to learn a skill-oriented sport—such as golf, tennis, or fly-fishing—you know what I mean. Once technique begins to break down you are no longer refining the skill—you’re simply ingraining bad habits.

How do you go about improving running and biking economy? Before getting into that, we need to determine which aspects of the above formulae to focus on—stroke/stride rate or gear size/stride length.

Cadence and Running

Let’s start with running. It’s a simple human activity, but it’s amazing how few know how to run. When adults take up running for fitness they typically lope along trying to maximize stride length with a slow cadence thinking this is the way to run fast. To get the long stride they have to raise their center of gravity by a few inches with every step. This has several implications.

The first is that a lot of energy is needlessly expended in running a race—the finish line is in a horizontal direction, not a vertical one. The second implication is that once up in the air the loping runner is dependent on gravity for a return to earth. On this planet, all bodies fall at the same maximal speed—32 feet per second per second. A great vertical displacement means slower running times due to this phenomenon alone. The third implication of loping is that when the runner does come back to terra firma from a height of a few inches there is a considerable impact force. Repeating this a few hundred times in each mile is more than most bodies can handle resulting in overuse injuries that plague runners.

So the answer to faster running is not a longer stride, at least not when trying to improve your running, but rather a faster cadence. This will minimize vertical displacement allowing you more frequent contacts with the ground (which is when horizontal power is applied) and decreasing the risk of injury since the landing is lighter.

The next time you watch a race with world-class runners, count their right-foot steps for 20 seconds. Even toward the end of a marathon what you’ll almost always find is that they take 30 or more right-foot steps—that’s a cadence of at least 90 rpm. Even when running slowly you’ll find their cadence is relatively high. They aren’t loping along at 80 or 85 rpm. That makes them very economical. If you don’t believe me, count the race leaders’ steps when you watch in the Boston Marathon this month.

Cadence and Cycling

How about cycling? Does the cadence vs. gear size argument hold true here? While gravity does not play an important role in the actual pedaling mechanics on a bike, the issue is somewhat more complex than for running since there is an interaction between a human and a machine. How well they fit together is a significant determining factor in selecting an economical cadence. For example, short crank arms favor pedaling at a high cadence and a high saddle position slows the cadence.

The cadence you use determines how you will feel in a race. Low cadences, for example, put stress on the knees and muscles and require greater muscle force generation than high cadences. High cadences require great metabolic effort (heart and lungs). This means that a high cadence would minimize muscle fatigue, but have negative implications for energy production and utilization.

Observations of elite riders in time trial events reveal a common cadence range of about 80 to 100 rpm. This range is also supported by much of the recent research. Studies dating back to 1913 have shown the most economical cadence to vary from 33 to 110 rpm. Recent, more sophisticated studies, however, have tended to favor higher cadences.

A good example of this is Lance Armstrong who is reported to have improved his time trialing for the 1999 Tour de France, which he won, in part by increasing his cadence from the mid-80s in previous years to about 100 rpm.

The bottom line is that it appears that once your bike is set-up correctly, pedaling at a cadence in the range of 80 to 100 rpm during a flat time trial is probably best. If you typically turn the cranks at a slower rate than this, it may help your race performances to become comfortable with a higher cadence.

Learning High Cadences

Economy can be improved if you work at it. This will result in faster race times, but it will take time to accomplish. One study using Swedish runners found that economy continued to improve 22 months after VO₂max had plateaued. It takes a long-term dedication to improving economy to realize the benefits. A brief experiment of only a few workouts just won’t do it.

Are you already so economical that further work at it is unnecessary? That’s doubtful. In the early 1980s, running legend Steve Scott improved his economy by a whopping six percent just before setting a world record for the mile. If an elite runner who already has excellent economy can improve by so much, what can the rest of us do? A one-percent enhancement in running economy can shave in the neighborhood of 20 to 30 seconds off of your 10k time. What would a six-percent improvement mean for your race times?

The accompanying “Run Cadence Drills” and “Bike Cadence Drills” are meant to train your nervous system so you run and bike more economically with higher cadences. At least one workout such as those described here should be done on a weekly basis year round to get the best results.

Joe Friel is the author of The Triathlete’s Training Bible. A free monthly newsletter and answers to frequently asked questions on the topic of this article and others are available on his web site at http://www.ultrafit.com.

SIDEBAR:

Run Cadence Drills

Step counting. During an easy to moderate endurance run count your right-foot steps for 20 seconds and multiply by three several times. Even at a slow pace your cadence should be in the mid-80s. If it’s not, increase the cadence slightly. You’ll probably have to shorten your stride to do this.

Strides. Once or twice each week go to a grassy park or other area with a soft surface. Find a straightaway that is very slightly downhill. After warming up run at faster than 5k race pace for 30 right-foot steps. Time this. Your time for 30 steps should be 18 to 20 seconds. Walk back to the start point after each one. Do five to eight such strides in a session.

Pick-ups. During an otherwise easy run, insert several 5k-paced pick-ups of 30 steps each. Just as with strides, time each of these pick-ups aiming for a sub-20-second time. Run very easily for about five minutes between pick-ups.

SIDEBAR:

Bike Cadence Drills

Isolated Leg Training. On an indoor trainer, pedal with one leg only as the other foot is resting on a chair or low stool. When fatigue begins to set in, which will happen frequently, switch legs. While pedaling focus on smooth mechanics by pushing your toes forward in the shoe at the top of the stroke or by getting the feeling that you are “throwing your knees over the handlebars.” Relax.

Spinning. Ride in the small chain ring on a flat course or indoor trainer. Keep your cadence at the high end of your cadence comfort range. Check your cadence. Focus on relaxation and skills developed by isolated leg training. When on the trainer try to produce a steady “whoooosh” sound instead of “whoosh-whoosh-whoosh.” The steady sound indicates you are smoothing out the transitions at the top and bottom of the stroke.

Spin-ups. Several times during a ride shift to a very low gear, such as 39 x 19, and slowly increase pedaling cadence to your maximum for 30 seconds. You’ve reached max when you start to bounce on the saddle. At that point slightly slow the cadence until the bouncing stops and hold this cadence for a few seconds. Learn to relax at high cadence. Recover for four to five minutes and repeat several times. A cyclocomputer with a cadence mode is useful for this drill.