Cyclists who train with a power meter often talk about their FTP value, making it an important performance indicator. A better FTP value generally means better performance, especially when expressed as power per kilogram of body weight. Many training plans for cyclists use Functional Threshold Power (FTP) as a basis to improve performance. This article explains what FTP is and which training methods can help improve your FTP value.
What is FTP and why is it important?
During exercise, various processes take place in your body, and as the intensity increases, these processes change. At low intensity, your body generates energy using oxygen (aerobic efforts), whereas at high intensity, your body primarily generates energy without oxygen (anaerobic efforts). This is a gradual process where the aerobic contribution decreases while the anaerobic contribution increases.
During anaerobic efforts, the body produces lactate (acid build-up), which it can also process. Each athlete has an intensity at which lactate production and lactate clearance are balanced—this is called the lactate threshold. In scientific literature, this is also referred to as the Maximal Lactate Steady State. The power you sustain at your lactate threshold is called Functional Threshold Power.
A higher FTP value means you can sustain more power before your body starts accumulating acid build-up. When expressed as power per kilogram of body weight—such as an FTP of 3.5 watts/kg—it directly correlates with your climbing speed. On a one-hour climb like Alpe d’Huez, losing a kilogram while maintaining the same power output will make you one minute faster. Additionally, training zones in a training plan for cyclists are calculated as percentages of your FTP.
Different tests to determine your FTP
The best way to measure your FTP is through a lab-based exercise test under the supervision of a sports scientist. A lab test can show your strengths as a cyclist, assess your aerobic fitness, and determine your lactate threshold/FTP value. The test must follow the correct protocol, starting at 80-100 watts and increasing by 30-40 watts every 3-5 minutes. Many sports physicians conduct a VO2max test, but this often overestimates FTP because the power increases every minute by 20-30 watts.
Since lab tests were not always accessible in the past, field tests were developed to estimate the lactate threshold. The 20-minute FTP test is a good example. After a proper warm-up, you ride a 20-minute time trial, and around 95% of your average power during this test is a reasonable estimate of your lactate threshold. However, this test is less accurate than a lab test and has limitations—a good coach can help interpret the results and refine your training accordingly.
Physiology of FTP/lactate threshold
To improve your FTP, you need to understand what happens in your body and what determines your FTP value.
VO2max
One of the key components of your FTP value is your VO2max, which is the maximum amount of oxygen your body can use during exercise. VO2max represents your aerobic energy production capacity, while FTP is the highest power you can sustain over time as a proportion of your VO2max. In most cases, a higher VO2max also leads to a higher FTP value.
Your FTP/lactate threshold as a percentage of your VO2max
To improve your FTP, it is useful to know where your lactate threshold sits relative to your VO2max power. A lab-based test will determine both your FTP and your VO2max power (which is not the same as your maximum sprint power). Professional cyclists have an FTP around 90% of their VO2max, whereas less-trained cyclists have a much lower percentage. If you have a strong aerobic base, your FTP should be at least 80% of your VO2max. This means you can improve your FTP by increasing your VO2max or by raising the percentage of FTP relative to VO2max.
Training methods to improve FTP
You can improve your FTP by increasing your VO2max and by raising the percentage of FTP relative to VO2max. Both aerobic and anaerobic training play a role in improving FTP. Essentially, every training session contributes to FTP improvements. Using a structured training plan ensures the right balance between endurance and high-intensity sessions.
Long endurance rides
Endurance training is crucial for improving FTP. As your aerobic base improves, so does your FTP/lactate threshold. An endurance ride doesn’t need to be long, as long as the intensity is low enough. For professional cyclists, long endurance rides are more important than for those with limited training time. These rides increase the number of mitochondria (energy factories) in your muscles and improve capillary density. The more mitochondria you have and the better they function, the higher your VO2max.
Less experienced cyclists often ride their endurance sessions too intensively. This is evident in lab tests, where their FTP/lactate threshold is lower relative to their VO2max.
Tempo/sweet spot training
Tempo or sweet spot training is done just below FTP. Since lactate accumulation is minimal, these sessions build less fatigue, allowing you to train closer to your current FTP for extended periods. While popular in the past, they are now used less frequently as more intense intervals have proven to be slightly more effective. During the winter period, this intensity is ideal for strength training on the bike with low cadence.
Threshold training
Training at or slightly above FTP helps improve FTP. These sessions are only recommended if your aerobic base is well-developed, as training above the lactate threshold leads to higher acid build-up and requires longer recovery. By training at this intensity, your body becomes more efficient at clearing lactate, allowing you to sustain higher power before acid build-up exceeds clearance capacity, effectively raising your FTP.
VO2max training
VO2max training aims to increase VO2max, which in most cases also leads to a higher FTP. However, these workouts should be used sparingly, as they cause significant fatigue and can reduce aerobic base fitness if overdone. VO2max intervals are short efforts of 2 to 5 minutes above lactate threshold.
A higher FTP does not always mean better performance
Whether a higher FTP improves performance depends on your training and testing methods. A lab test provides a snapshot of your fitness, showing whether your aerobic base is sufficient and where your lactate threshold sits relative to your VO2max.
Many cyclists rely on 20-minute tests or other field-based FTP tests, which do not assess aerobic base fitness or explain FTP improvements. It is easy to improve a 20-minute time trial, partly through pacing strategy. However, with each FTP increase, training zones also rise, potentially leading to overtraining. Some riders achieve high FTP scores in these tests but struggle to complete races or long endurance rides. Using structured coaching ensures the right balance of endurance and intensity to maximise FTP improvements effectively.
