INTENSITY ZONES. THE DIFFERENCE BETWEEN THE AEROBIC AND ANAEROBIC THRESHOLD
There are three intensity zones clearly marked by different thresholds: The first zone goes from resting to the aerobic threshold (VT1). The second zone is between the aerobic threshold and the anaerobic threshold (VT2). The third zone is the one between the anaerobic threshold and the athlete’s maximum capacity.
Clearly, these three zones are general and don’t specify much in terms of the intensity of the activity itself. For example, when riding in zone two, the big difference will be riding close to the aerobic threshold (65%) and riding near the anaerobic threshold (80%).
In an attempt to be more specific, the now well-known five training zones were created. These are the zones that the majority of pulsometer manufacturers have incorporated into the configuration of their heart rate monitors. These five zones arose by dividing zone two and zone three into two separate zones.
CYCLING TRAINING ZONES IN POWER TRAINING
Our last post discussed “Power Training”, listed the benefits of power training, and contrasted them with the drawbacks of training by heart rate zone. So, when you’re determining your power training zones, know that there are seven zones set based on each cyclist’s FTP (functional threshold power).
As you can see, power training allows you to see training zones more precisely, provided your FTP is up-to-date.
There are a number of methods to calculate your exact FTP, but the simplest and most common method is known as P20 or the 20-Minute Test. The idea of the P20 is to ride at maximum effort along a constant route (no downhill sections). Unless you are training and have set objectives for flat routes, the usual recommendation is to do P20s at a constant incline (6-8%). Once you get your 20-minute average power, a correction factor is applied. Different authors place that correction factor between 92 and 95%.
It is worth noting that the correction factor is applied to convert the average 20-minute power into the average watts the cyclist would have generated in one hour. This means that if a cyclist gets an average of 300 w in the P20, they’d multiply 300 w by 0.95 to obtain their FTP. 300 x 0.95 = 285 w. If a 92% correction factor had been applied it would have been: 300 x 0.92 = 276 w.
It is worth noting that as you improve your FTP, your training zones will increase proportionally. So, it’s very important to update your FTP regularly (every 6–8 weeks).
Over the last few years, the seven training zones mentioned above have been extended to nine, with zones 4 and 7 divided into yet another two zones (zones 4a, 4, and 7a and 7). Dr. Andrew Coggan christened the new training zones “iLevels”.
THE IMPORTANCE OF TRAINING ZONES FOR CYCLISTS