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

(downhill), ride easy, meaning use lower power, but if you are riding on a slow portion of a course (uphill), ride hard, meaning use higher power. So when you ride fast on a downhill, don’t expend as much energy as when you ride uphill. Hold back on your power output when going fast. The longer the event is, the more important this is. That is, you can go much harder downhill for a 20-km time trial or a sprint-distance triathlon than for a 40-km time trial or an Ironman.
    The best advice I’ve seen for this concept came from Alan Couzens, an exercise physiologist and triathlon coach. He nailed it with his “50-40-30-20-10 Rule” for Ironman triathletes. The concept applies across all steady-state cycling sports with some possible modification. His rule is described in Table 5.2 .

    Of course, your planned speed may not be 19 mph. The concept, however, remains the same: Conserve energy when the bike is going fast (downhill); expend energy when the bike is going slow (uphill). The numbers in Table 5.2 can be modified to fit your race goals. If your goal is about 25 mph, substitute 40 kph for 30 kph and adjust the others accordingly.
    Setting up the table is the easy part. The real key to success is rehearsal. Every time you go for a racelike ride, incorporate the basic concept—ride slightly harder uphill, ride slightly easier downhill, and coast when you are going faster than your upper-end speed on the chart. You’ll conserve energy and produce faster bike splits by doing this.
BURNING MATCHES
    So far I’ve explained pacing with power only in steady-state events. Pacing is also critical in variably paced races, such as criteriums and road and mountain bike races—but in an entirely different way.
Matches and Variably Paced Races
    In variably paced races, energy expenditure isn’t anything like what is common in a time trial or triathlon. Road races, criteriums, and mountain bike races are “variably paced,” meaning that your power output will significantly change throughout. Your power at any given moment in such an event depends largely on what others are doing and on the terrain. You can’t ride steadily and expect to be a contender in the race. Staying with the group when it speeds up and matching its power surges on climbs are critical to the outcome. As explained above, you should expect to have a high VI in such a race.
    That said, it’s possible to start too hard in a variably paced race. You are likely to experience a lot of nervous excitement at the start line. When the guns goes off, if you bolt to the front and keep throwing in frequent surges,you’ll soon wear yourself out. Controlling your emotions is critical to success in all such races. You don’t win a race in the first several minutes, but you can certainly lose it.
    Even if you do control your emotions early in the race, some others almost certainly won’t. There are going to be many surges as different riders go to the front and drive the pace up. The less experienced the group is with racing, the more likely this is to occur. In the latter portion of the race, there are typically fewer surges, but they are more critical to the outcome.
    These surges often last only a few seconds to a couple of minutes at most. They commonly happen when riders are coming out of corners, going up a hill, or attempting to break away from the group. You must be able to respond to these surges, or even initiate them at the right times, if you are to finish well.
    Extreme surges are appropriately called “matches” because you get only so many, and once they’re gone, they’re gone. Given your fitness, you have only a certain number of matches to burn on any given day as you stand at the start line. If you needlessly waste them, you’ll have a poor race. But if you burn them in the right amounts at the right moments, you will do well.
    The starting place for sound match burnings begins with recognizing that yours are not unlimited and that they can be defined by intensity, duration, and volume: how high the power surge is, how long you maintain it, and how many matches you burn in a race. You can find all of this in postride analysis using WKO+ software. See the sidebar “ How to Set Up WKO+ for Matches ” for the details.
    You can define a match in any way that seems appropriate to you. Here’s what I do. For a road race or mountain bike race, I define a match as a surge that lasts 20 seconds or longer with sustained power in zone 7 (see