Power Vs. Duration in Cycling Exercises

Ask any cyclist who tracks her training statistics, and you'll find that power and duration are key. To become a stronger cyclist, it's imperative to systematically improve these two training factors. You've probably heard of athletes using power meters when they train, but many people don't quite understand what power is or how it's measured. Learn to utilize training power and duration to help you become a better cyclist.

  1. Power on the Bike

    • In athletic performance, power is a measure of the rate of energy used. The amount of energy you expend over time reveals your work rate -- that is, how hard your body is capable of performing for a prescribed period. Power is expressed as watts, the same unit of energy used to measure the output of household light bulbs. A fundamental measure of fitness that utilizes power measurements, known as "threshold power," is the amount of power output your body is able to sustain for an hour.

    How to Measure Power

    • To measure and track cycling power output, you'll need a power meter. Several manufacturers make these devices, including SRM, PowerTap, Quarq and Look. Power meters work by multiplying the force placed on a wheel by the speed at which it's rotating. Force is measured by the torque placed on strain gauge, which is set inside a component, such as a bike crank arm. Power meters can be expensive, ranging in price from around $900 to over $2,000. Although these are powerful training tools, cost is a major deterrent for many cyclists. If you can't afford a power meter but would still like to gauge power output, many models of cardio bikes found in health clubs have a computer function that estimates wattage.

    Training Duration

    • Duration is used to describe the total amount of time spent exercising. Duration of cycling can be increased as your body adapts to training demands, free of excessive fatigue or injury. Duration can be measured for individual training sessions or over longer periods, such as a week or month.

    Which Is More Important?

    • Power and duration are crucial training elements for most cyclists, but training focus should be based on your goals. For example, if you're an endurance cyclist, it's more important for you to focus on training duration, to prepare you for long rides. On the other hand, if participate in events that emphasize quick, explosive power, such as racing mountain bikes, cyclocross or time trials, you'll probably want to focus more on power training. For the average, noncompetitive cyclist, a solid fitness plan should provide an even mix of power and duration training.

    Improving Power and Duration

    • The two ways to improve power on the bike are to increase force or increase cadence. To increase force, focus on the amount of strength you put into each pedal stroke. If you're training on an indoor bike, you could improve cycling power by riding with heavier resistance. Outside, you can train to improve power by climbing a hill or riding against the wind. Cadence is easier to measure and doesn't require a power meter. Many bike computers include a component that provides a cadence reading. To improve duration, you should slowly increase the time you spend training. For most healthy individuals, a weekly increase in training duration of five to 10 percent is safe.