Power Zones
About Power Zones
Z7: Anaerobic Capacity (>120% OF FTP)
By working at power outputs high enough to elicit very high levels of oxygen uptake, tremendous improvements in both
aerobic and anaerobic power can be achieved, all in very little time. Short-duration, high-intensity repeats can be
highly productive for all types of riders but are especially important for riders working on limited training time. In
far less time than that required by long, slow distance approach to training, riders can develop similar aerobic
capabilities - little time, high stress, comparable adaptation.
Z6: VO2 Max (105% - 120% OF FTP)
VO2 Max efforts aim to increase your power during short, intense efforts and to expand your aerobic capacity, i.e. the
ability to utilize more oxygen more effectively. They also do a good job of stressing your intermediate muscle fibers
that process both fat and sugar and therefore utilize oxygen much like your slow-twitch, endurance fibers. When training
time is very limited, deriving a high training benefit in minimal time is crucial - this is how you do it.
Z5: Threshold (94% - 105% OF FTP)
By spending time very close to your FTP, riders can improve their sustainable power & muscle endurance by teaching their
muscles to process high levels of lactate and acidic buildup without slowing down. Additionally, and equally as
important, riders learn to tolerate the mental discomfort inherent in maintaining high levels of Functional Threshold
Power.
Z4: Sweet Spot (87% - 94% OF FTP)
Sweet Spot intervals aim to further muscular endurance and enhance aerobic capabilities. Additional related benefits
include improved sugar storage in the muscles, better utilization of fat for fuel, a higher capacity for more intense
workouts later on and increased power output at moderate, predominantly aerobic intensities.
Z3: Tempo (75% - 87% OF FTP)
Riding in the tempo range pushes you near the height of your aerobic endurance. While rather uncomfortable, working here
isn't terribly stressful and it allows you to spend long durations at a constant and productive work level with little
recovery. This is where many half-distance triathletes will live for 2+ hours during their bike leg. This is also where
ample time is spent during long road races, especially ones with steady climbs.
Z2: Endurance (55% - 75% OF FTP)
Aerobic Endurance workouts are aimed at improving your aerobic-power-producing capabilities in a low-stress manner. By
riding for increasingly longer periods of time, your endurance muscle fibers become more efficient at utilizing fat for
fuel and sparing sugar stores for more intense efforts. Additionally, Endurance workouts can improve oxygen delivery &
utilization, increase muscular resistance to fatigue, improve the integrity of connective tissue, and even help you
improve your on-bike nutrition strategies.
Z1: Active Recovery (<55% OF FTP)
Active recovery is a zone that you'll see in-between intervals as a chance to recover, catch your breath, and lower your
heart rate before digging in again for the next interval.
