The Vekta Edge: Understanding Durability in Cycling with Jeroen Swart

Durability in cycling is a hot topic among professional athletes and coaches alike, and its importance is becoming increasingly recognised. In this article, Jeroen Swart, Performance Coordinator for UCI WorldTour team UAE Team Emirates and Professor of Sports & Exercise Medicine, offers his insights into what durability means, how to measure it, and how athletes can improve it.

‍

What is Durability in cycling?

Durability is a term that's relatively new in the endurance sports world, having replaced the concept of "fatigue resistance" over the past few years. As Jeroen Swart explains, durability refers to an athlete's ability to maintain power output after prolonged physical exertion, especially in the later stages of a race.

Swart highlights that when an athlete is fresh, they have a predictable power-duration curve. However, after several hours of effort, that power output begins to decline, regardless of recovery periods. Durability is essentially the ability to minimise that power drop-off and maintain performance.

He emphasises that this fatigue isn’t immediately reversible, taking a day or more of recovery to fully restore an athlete’s power output.

‍

‍‍

Measuring Durability: A Complex Challenge

One of the major hurdles in understanding durability is how to accurately measure it. Swart explains that while there are methods such as monitoring kilojoules expended or work per kilogram of body mass, none are perfect.

Traditionally, a set number of kilojoules (e.g., 2,000–4,000) was used as a threshold to determine when fatigue might start to affect performance. However, this method fails to account for individual differences in body size. Larger athletes may find it easier to handle a high kilojoule workload, while smaller athletes might struggle.

A more effective approach, according to Swart, is to consider both relative and absolute power. Together with UCI WorldTour Coaches Peter Leo and John Wakefield, they developed a "composite score," which takes into account both absolute and relative power outputs. This method has been shown to be a good predictor of performance, especially in young athletes.

Realising the importance of durability, Vekta also allows users to analyse power files according to different levels of fatigue (from 0 to 50 kJ/kg). In addition, the current kilojoules expended will be displayed before an interval during a workout.

Read more about the “Compound Score” in Road Cycling here

‍

‍‍

The Impact of Intensity on Durability

It’s not just the total workload that matters when assessing durability, but also the intensity of the work done. Swart notes that sub-threshold efforts (below the athlete's Critical Power, or FTP) don't significantly affect durability. However, efforts above Critical Power such as sprints or surges have a much more profound effect on an athlete's ability to maintain power later in a race.

To measure this, Swart’s team at UAE Team Emirates uses a protocol that includes high-intensity intervals followed by maximal efforts, which can help gauge how well an athlete can maintain performance after fatigue-inducing efforts. “We do five, eight minute intervals at a hundred and five percent of FTP with 15 minute recovery periods in between. And after that, we measure durability by doing a maximal effort for a particular period of time.”

‍‍

Training Strategies to Improve Durability

Swart emphasizes that improving durability is a multi-faceted process that combines nutrition, functional strength, and aerobic endurance work.

One of the key elements is nutrition, particularly during long races. Advances in sports nutrition have allowed athletes to consume upwards of 110 grams of carbohydrates per hour, helping to maintain energy levels and stave off the worst effects of fatigue. This, according to Swart, is one of the biggest changes in cycling over the past decade.

Training-wise, Swart points out that durability develops over time, especially for young athletes transitioning from junior to elite levels. While VO2 max remains important, it’s no longer the sole indicator of performance. Swart notes that metabolic profiling, looking at how efficiently an athlete uses fuel, is a far more valuable tool when it comes to predicting durability.

‍

‍‍

Functional Strength and Mental Toughness: The Underestimated Factors

Functional strength also plays a crucial role. Athletes with greater functional power (measured in Newton meters per kilogram of body mass) tend to show better durability over time. Swart's research has shown that functional strength, developed through targeted interventions, can significantly improve an athlete’s durability. “We've seen that with UAE Team Emirates in the last 24 months, and we've seen that with other athletes as well.”

Mental toughness is another often-overlooked factor in durability. Swart notes that athletes who are mentally fresh and focused are better able to maintain power outputs, especially in the later stages of a race. This mental resilience can be cultivated through having “strategies in their daily life and in terms of their training, that give them a lower mental stress”. 

‍‍

The Pitfalls of Over-Specialization

One common mistake that athletes make when trying to build durability is focusing too narrowly on one aspect of training, such as endurance or strength. According to Swart, an overly focused approach can lead to imbalances, with athletes losing other important attributes in the process. To build true durability, athletes need a balanced approach that incorporates all aspects of training, from strength work to aerobic conditioning and mental preparation.

‍

‍‍

Durability in Action: Real-world examples

Swart cites several real-world examples of how durability impacts performance. One example is Jan Christen, a talented young rider who transitioned to the WorldTour but initially struggled with the longer, more demanding races. However, through focused training, Christen is developing the durability needed to perform at the highest level and has performed much better in the 2024 season.

We also touch on the recent trend of younger riders performing very well at WorldTour level, citing the example of Remco Evenepoel. Swart points out that today, younger riders are benefiting from better access to training resources and scientific knowledge, allowing them to develop durability at a younger age.

‍

Building Durability for Long-Term Success

Durability is not just about enduring physical fatigue; it’s about maintaining performance in the face of that fatigue. As Jeroen Swart’s insights show, building durability requires a holistic approach, combining proper nutrition, metabolic efficiency, functional strength, mental toughness, and balanced training strategies.

For cyclists looking to improve their durability, it’s essential to focus on both the physiological and psychological aspects of performance. By doing so, athletes can enhance their ability to perform at their best, even after hours of grueling effort.

Discover more about how Vekta as a platform can help a coach increase an athlete’s durability with data-driven insights here.