Zone 1: Recovery- less than 55% of FTP
Zone 2: Endurance- 56-75% of FTP
Zone 3: Tempo- 76-90% of FTP
Zone 4: Lactate Threshold- 91-105% of FTP
Zone 5: VO2max- 106-120% of FTP
Zone 6: Anaerobic Capacity- 121-150% of FTP
Zone 7: Neuromuscular Power- Over 151% of FTPSince you don't train for "Recovery", there are six zones to train in order to be a well rounded racer. Endurance and Tempo zones are typically trained on your long days or group rides. For the threshold and anaerobic zones, interval or repetition training is the best way to improve. The real question is do you know the difference and when to use interval or repetition?
Interval training is primarily designed to increase your VO2max levels. Lets say you wanted to do a VO2max interval that would last 8 minutes. How long will it take your heart rate to get into the zone and how long will it take for the goal power numbers to be challenging? If your goal power for the interval is 280 watts, it might take two minutes for that to feel challenging and for your heart rate to start rising. This means your 8-minute effort is only 6 minutes at your goal. The following is 8 minute intervals as shown with power and heart rate:
Obviously it is important to practice these long intervals to improve muscular endurance at the higher power ranges. Next take a look at an interval set designed to improve VO2max also. These are actually listed as anaerobic capacity intervals because they are done at a higher power level. These intervals have an equal rest as they do work, but the rest could be less for these types of intervals. They train you using a higher power level, but your heart rate responds like a VO2max level. As these intervals increase in numbers, you can see the power is decreasing, it is alright. The heart rate is also not coming down as quickly between intervals and climbing quicker. The real training occurs as this workout progresses.
Finally I wanted to show you repetition training. These are efforts that have much longer rest intervals than they do work intervals. The goal is to be near full recovery before starting the next effort. These are specifically designed to improve power output at a specific zone or time period. The design here was a specific power to hold until he hit fatigue. Then he rested for at least 2x the work interval and repeated.