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

long or hard ride. Between the longest ride and the recovery rides are workouts that focus generally on higher intensity.
Intensity
    For the experienced cyclist, training is mostly about intensity. Sport science research has repeatedly shown this to be true. If all you do as an experienced athlete is ride long sessions at low intensity with an emphasis on weekly volume, you will never achieve anything near your potential in sport. How important is intensity? If I had to put a number on it, I’d say that intensity accounts for about 60 percent of your fitness. Most of the remaining portion comes from the duration of your key workouts. Weekly volume is a distant third.
    This doesn’t necessarily mean training at the highest intensity possible but rather training with an emphasis on riding at about race intensity, especially in key workouts. A key workout is one intended to challenge and therefore improve some aspect of your fitness related to the six training abilities described in Chapter 4 . The hardest key workout is always one that closely simulates both the duration and the intensity of the event. It’s also the workout most likely to prepare you for the rigors of your race. Do not sacrifice intensity of such a workout simply to ride longer. It’s not a good trade-off.
Workload
    Workload is the sum of frequency, duration, and intensity. It can be expressed for a single workout as the combination of duration and intensity or, for a given period of time, such as a week, as a blend of all of three.
    For a single workout, as either duration or intensity increases or decreases, your session workload also increases or decreases. Long rides at a low intensity can produce the same workload as short rides at high intensity. This doesn’t mean that the resulting fitness is the same. Fitness is a separate matter having to do with how specifically the duration and intensity of workouts are designed relative to the targeted race. But the session workload can be the same no matter what mix of duration and intensity is used.
    Weekly workload is the combined result of a week’s volume (frequency + duration) and intensity. Athletes tend to think of workload strictly in terms of volume: how many hours or miles in a week. Based on what I’ve told you, that is hardly the best way to describe workload because it leaves out the most important ingredient: intensity. It’s not how many miles but what you do with those miles that makes the most difference on race day.
    Workload can be determined for a day, a week, a month, a year, or any other unit of time, such as a training block. Knowing your total workload for a given time allows you to better manage your training and therefore your race performance. By increasing the workload, you can improve fitness; by decreasing it, you can recover. So how do you combine volume and intensity to put a number on your workload? That’s where a power meter once again can provide a solution.
Training Stress Score
    Hard training causes stress. In fact, stress is what good training is all about. When your body experiences training stress, it responds by first becoming fatigued. Then, usually within hours and given adequate recovery, it begins to adapt to the new level of stress. We call this adaptation “fitness.” After a single stressful workout, this new level of fitness is so minute it can’t be measured. But if the stress is applied over several days at an optimal rate—not toomuch but just the right amount for you—then the fitness change becomes measurable. You can produce more power, ride faster, and manage greater levels of stress.
    It should be obvious that if you can handle more stress now than you could a month ago, then you are fitter. For now, just for the purpose of understanding the basics of workload, let’s examine stress in terms of only one of its components: volume. We’ll omit intensity for now. Let’s say, for example, that this week you rode for a total of 16 hours, and that was just barely manageable, meaning you were tired but not totally wasted by the end of the week. But a month ago you could cope with only 12 hours as that put you at your limit. Based on this change, I think you would agree that you are in better shape than you were a month ago. Your fitness has improved. If a month from now your weekly volume is 20 hours and it doesn’t wipe you out, then you are, once again, seeing an improvement in fitness. So how much stress you can handle over a period