When I start working with an athlete, one of the first things we accomplish is a series of tests to determine training zones to establish intensity and volume levels to maximize future training benefits. The test protocol that has become an industry standard when using bike power is the functional threshold power (FTP) test. FTP is a critical metric for establishing power-based training zones. When Dr. Andy Coggan developed the FTP performance metrics, he originally defined FTP as “the highest power a rider can maintain in a quasi-steady state without fatiguing for approximately one hour.” Within the past few years, Dr. Coggan has redefined FTP to “the highest power a rider can maintain in a quasi-steady state without fatiguing.” The basic test is 20- minutes to caclulate the highest average wattage over the entire period, minus 5%. I predominantly use the 20-minute test for athletes without past training logs or athletes new to the sport. With conditioned athletes, I use a testing period starting with a 30-minute test and often extend to 60-minutes using the highest average wattage over the entire period to establish FTP. When the test is complete, we can set FTP and divide the result into specific training zones. When athletes train in distinct zones, they apply a measured amount of intensity, improving targeted areas of their physiology. For the endurance athlete, building and maintaining fatigue resistance is the primary goal of most of our training.
Once power training zones are established, we recognize each zone has a particular psychological response, with each zone allocated to an explicit training phase.
If we do some research online, we will discover many variations of power zones with varying degrees of intensity, which may confuse the athlete. I use an eight-zone system when coaching my athletes on the bike, but you may find other protocols with seven, six, or five levels of intensity. There is also a good argument for the old-school methodology of easy, medium, and hard as a good judge of intensity levels. The primary reason for such diversity in training zones is physiological overlap within certain zones. For example, we have similar physiological benefits with zone four sweet spot and zone five threshold, including increased lactate threshold, muscle capillarization, and stroke volume. So even though physiological benefits are similar between power zones four and five, the athlete generally recovers faster from a sweet spot workout, so if the goal is to increase fatigue resistance I will typically prescribe a sweet spot. However, if we’re trying to raise FTP, I will see greater returns by prescribing threshold workouts, keeping in mind this may impact the next day’s training. Even though the zones have the same physiological benefit, the zones are quite different from the athlete’s perspective and the desirable outcome.
Another example of a more targeted approach to training zones is to look at zone three tempo 77% to 86% FTP. Zone three is typically the zone many athletes are racing the half-ironman distance at if their power zones are accurate and the athlete is conditioned. However, as many of you are aware, there is a big difference between riding fifty-six miles at 77% of your FTP or 86% of your FTP on race day. Again, the physiological benefit is primarily the same across the zone, but a few percentage points can make a difference in training, recovery, and race day performance.
When preparing an athlete for a race, the training is less specific at the beginning of a block. The workout may have a wider margin within a particular zone, like 76 to 86% of FTP. As the race gets closer, the training may only have a gap of a few percent. For example, the workout may be written at 85 to 86% of FTP, increasing the volume until we are near the race distance. Then, I use a power duration model to gauge the increase in fatigue resistance at the prescribed power output.
This specific training is not for everyone. Maintaining exact power numbers when riding outside with varying terrain or in heavy traffic is often challenging. It also takes a fair amount of discipline to crank out hours on the trainer. However, the data provides vital insights into an athlete’s fatigue resistance at a specific percentage of FTP. The goal is not to see any decrease in power output during the race and still be able to run at or below the predetermined race place.
Research has shown the value of training in given zones to increase performance on race day, and we know there is an overlap of the physiological benefits between certain zones, with every athlete responding to training intensity and volume differently. However, using power is an exact indicator of your performance, and fine-tuning your training zone may provide a more significant increase in performance and fatigue resistance than training within a broader power zone.