The Power Meter Handbook: A User’s Guide for Cyclists and Triathletes

small cogs with a cadence of 60–70 RPM. Experienced riders, in contrast, commonly use gears that allow them to spin the cranks at a much higher cadence; 85–95 RPM is common for well-trained riders. Research has shown that such a cadence is effective and efficient for seasoned cyclists. Part III will get into the details with specific workouts to increase cadence by sport.
Basic Training
    Whether you do workouts with or without a power meter, the basic training philosophy remains the same. What’s changed once you start using power is the methodology: how you gauge riding intensity, design workouts, and analyze workouts and races. The common training-philosophy denominator continues to be stress.
    In order to pedal with more force or a higher cadence, you must stress the body. In other words, you must do things in workouts that are slightlymore challenging than what you’ve previously been doing. And then allow for a day or so of rest. During rest the body begins to adapt to the new level of stress, provided it wasn’t excessively hard.
    The changes that take place occur in the three determiners of fitness as described in exercise physiology textbooks: aerobic capacity, anaerobic threshold (AT), and economy. Let’s take a quick look at each of these, as their combined changes—owing to your training—ultimately determine how fit and fast you are.
Aerobic Capacity
    Also called “VO 2 max,” aerobic capacity is a marker of fitness that has to do with how much oxygen your body is capable of using when producing high levels of power. The more oxygen that’s used when you are going at maximum intensity for several minutes, the higher is your power and the greater is your fitness. VO 2 max is expressed as a number reflecting your maximum milliliters of oxygen used per kilogram of body weight per minute (ml O2/kg/min). World-class male cyclists typically have VO 2 max values above 70. The rest of us mere mortals have somewhat lower numbers. The value is about 10 percent less for women and declines as we all get older.
    We look at VO 2 max as one measure of endurance fitness because the energy needed to power the pedals calls for fat to be burned. Fat metabolism is based on the utilization of oxygen. When more oxygen is used at a maximal endurance workload, more fat is burned. And more power is generated. Training with a power meter will allow you to design your workouts to increase your VO 2 max and also to quite precisely measure your resulting performance gains. Neither option would be feasible without a power meter.
Anaerobic Threshold
    Anaerobic threshold is the point where, in a hard cycling effort, you start to close in on your limit. This point is sometimes called “lactate threshold” instead. You may also read about “ventilatory threshold” or even “OBLA” (onset of blood lactate accumulation) and “MLSS” (maximum lactate steady state). Sports scientists would be quick to point out the differences among these markers of intensity. But for our purpose here, we’ll simply say that they all have to do with the submaximal intensity at which you begin to “redline” (hit the limit of your long-term, sustainable effort). At such an intensity, you experience labored breathing and realize that you won’t be able to stay at this effort for long. On a rating of perceived exertion scale from 0 to 10, with 10 being maximal, you’re at about a 7 when you reach your anaerobic threshold.
    AT is generally expressed as a percentage of VO 2 max. Riders with very good fitness have ATs around 85 percent of VO 2 max. For example, a fit amateur rider with a VO 2 max of 60 and AT at 82 percent would be using oxygen at the rate of 49 ml O2/kg/min when at the anaerobic threshold. Less-fit athletes will have lower AT percentages. The closer you can get your AT to your VO 2 max, the fitter you are and the faster you can ride. Although VO 2 max rises only in small amounts over the course of a year for a seasoned athlete, AT can rise considerably more—if training is effective.
    Again, with your power meter you’ll know exactly what it takes to ride at or near AT, thus allowing you to stress and, ultimately, improve it. That simply means you’ll race faster once your AT is higher. We’ll come back to AT many more times in the following chapters as we discuss training with power.
Economy
    You’re undoubtedly familiar with this term from an understanding of the “economy” rating of your car: its miles per