Whilst the average cyclist has been embracing heart rate monitors, aero equipment and various sports nutrition ergogenics, the professionals have been one step ahead, testing, training and racing with power.
Power (or in the case of cycling, the amount of watts) is the rate at which work is performed, or how much work is done in a certain amount of time. Put simply, power measures the work you are doing, unlike heart rate, which shows how much strain your body is under. This does not mean it's time to throw away heart rate monitors - both power and heart rate can be used to see how well you are riding.
Even back in 1972 the great Eddy Merckx underwent laboratory tests to obtain his best one-hour effort and probably averaged around 450 watts. A quarter of a century later, another five-time Tour de France winner, Miguel Indurain, put out 500 watts in track and lab tests before his hour record.
To put this in perspective, a good club rider is likely to average around 280 to 310 watts an hour.
Despite the professionals developing more power, and the bulk of information coming from track data, it is still relevant to road racers, the club run, triathletes and even mountain bikers. In fact, a recent interview with Mountain Bike National Champion, Oli Beckinsale, revealed he does 400-watt intervals, using power-measuring SRM cranks. Data from Road racers shows the average effort over a six-day race was 220 watts, with 167km flat stages as low as 190 watts and a 13km time trial over 390 watts. If you want to really increase your pace over long distances, sprinting ability, or power against the wind, power-based training is the way to go.
The advantage training with power gives over, say, guess work or heart rate, is the ability to put in the exact effort required. Intervals become specific targets of work rather than just getting your heart rate up. To sustain the same power output in a series of intervals, such as 7x4min, heart rate may increase 10 to 15 beats. Therefore, if the rider had been using heart rate to judge effort, the power would be dropping as the intervals progressed.
Research using specific power intervals shows that improvements can be made in various ways ('peak power' is the sustained power in the final stages of a progressive 'ramp test' . This may increase by 10 to 30 watts over a six-week training period.)
Compared to many technologies, a power sensor system is really good value for money. It works for you on recovery days to keep you off the steep hills and makes you work hard on the interval days.
Look at how many pro teams now use power all year round.
Even an indoor trainer with power is better than guesswork. Graeme Obree, still knocking out 19-minute, 10-mile time trials, still uses his Cateye indoor trainer to do intervals and gain form. Many other club riders use power-measuring systems to test their peak power, or to hit key 'interval efforts' indoors. The craze for power is growing...
With no power-measuring system, indoors or out, you are guessing and are, therefore, probably not performing at your best. Although there is still much to learn about power, we know one thing already: it makes better riders out of those who use the systems correctly. Power to the people.