Multisport: Cycling Economy - Is it a better fitness predictor?

Written by: Edmund R. Burke, Ph.D.

Although most top cyclists, have high VO2 max (maximal oxygen consumption) values and lactate thresholds, and while both are good predictors of performance, recently coaches and scientists have begun to look at a third factor to determine fitness and efficiency of effort.

Cycling economy is often regarded as one such important test of cycling performance. The amount of oxygen required during a given exercise level is an essential component of on the bike performance.

Economy to a cyclist means exactly the same thing as economy to an automobile driver: the ability to do a certain amount of work using as small amount of energy as possible. You want to conserve gas in your car. You want to use a lower percentage of your VO2 max at a given cycling speed. Both examples represent economy.

"I would say that economy is one of the single most important determinants of success at the elite level of road and off-road cycling," says Jay T. Kearney, Ph.D., Senior Exercise Physiologist for the U. S. Olympic Committee. "If two cyclists have similar VO2 max profiles, the most economical cyclist will win most races. Even if a cyclist has a relatively low VO2 max, he can often defeat other cyclists, because he may ride at a lower percentage of his maximum at any given speed." If two cyclists are riding at the same speed, the more economical cyclist uses less oxygen to ride at this speed.

An uneconomical cyclist may need to use 5 to 10 percent more energy (or oxygen) than an economical cyclist to cycle at a given pace. The uneconomical cyclist will be working closer to their maximal capacity than an economical cyclist. Since the physiological strain felt by the body is directly related to VO2 max, the economical cyclist will have an advantage. In other words, the more economical cyclist will be able to ride faster while experiencing less fatigue.

An example of the power of economy can be seen as follows: Two cyclists enter a hill climb or time trial. Both have the same VO2 max, but Cyclist A is more economical. They both ride at the same high speed. However, to reach and maintain this speed, Cyclist B must ride at a pace equal to 95% of his max VO2. Cyclist A, on the other hand, can ride the same speed, yet only be at 90% of his max. Should he pick up effort to 95%, he would out ride Athlete B and win.

Training has been shown to improve economy. If, after training, economy has really been improved, the oxygen cost for each intensity should be less. In addition to training, another way to improve economy is through biomechanical assessments. Frequently, a film analysis of a cyclist while riding is used for this. From high speed films, joint angles and forces can be calculated.

If you, too, want to improve your economy what can you do to improve your performance. First you have to improve your pedaling mechanics, learning to pedal smoothly and correctly can help your pedaling be more effective. In other words, improve your pedal force application from top dead center, through the bottom of the pedal stroke. Practice pedaling smoothly and learn how to spin rather than pushing big gears. Learn to be more economical on the bicycle.

Normal pedal force is most pronounced during the power phase of cycling (zero degrees to 180 degrees) and typically peaks between 90 and 110 degrees (shortly after the crank arm passes horizontal). Most cyclists can become more economical by delivering energy to the pedals over a greater percentage of the pedal cycle by "pushing through" at the top and "pulling back" at the bottom of the pedal stroke. Dr. Jeff Broker, biomechanist with the U. S. Olympic Committee points that, "Any increase in force effectiveness in these regions, by all cyclists, and/or during the recovery phase of the pedaling cycle (180 to 360 degrees of the pedal stroke), results in the following: a lower demand on the musculature of the leg in the power phase at constant pedal power or greater bicycle power output (speed) for the same power phase effort.

Other factors waste energy without propelling the bicycle forward will affect economy. Fighting the bicycle, holding the handlebars too tightly, using a lot of upper body energy while climbing and riding is an unaerodynamic position during time trials or break-a-ways will affect your economy. Finally, you can improve your economy by increasing your interval and tempo training. The theory behind this is that by practicing fast cycling, you naturally become more economical and relaxed while riding fast. Once you've trained your body to respond economically at these speeds, it will most likely be even more efficient at the slower speeds during long road races.

Off-road cyclist can also learn something from testing their economy at various workloads. At a testing session of elite mountain bike cyclists at the Olympic Training Center several of the male cyclists recorded VO2 max's of over 75 ml/kg/min. (oxygen consumption in milliliters per kilogram per minute) while reaching workloads of over 450 watts at maximum.

These off-road athletes were then compared to the hundreds of elite road cyclists that have come through the physiology laboratory in Colorado Springs for testing. It was found that this group of elite mountain bike cyclists were less economical than many of the elite road cyclist that have been tested at the training center. Discussion among the group of scientists, coaches and athletes pointed out that this may be due to their increased use of their upper body's in pulling on the bars while even cycling at submaximal workloads. "You can improve your economy on the bicycle by improving your pedaling mechanics and eliminating unnecessary muscle movements, you must learn to relax your upper body while cycling hard," noted Jay T. Kearney, to the group during the data return session. "This same information holds true for all of us, no matter if we ride the roads or trails," added Kearney.

Performance in off-road and road cycling depends on training time on the bike, a high VO2 max, effort spent on skill development, improving strength and having a high economy of effort, or low VO2 value for the same rate of work. Don't leave anything for granted- especially your economy of effort.