Cyclocross heroes seem to dominate in road cycling. How do cyclists like Thomas Pidcock, Wout van Aert and Mathieu van der Poel make the switch from a 60-minute cyclocross race to a 6-hour road race? In this blog, Wout van Aert – coached using INSCYD since 2017 – reveals his secret!

In cyclocross, it is important to be explosive. Riders need to be able to accelerate after a corner and survive a sandy or hilly section. From an energy perspective, this requires a fast energy production to be able to increase the power on the pedals.

STEP 1: understand the different race demands of cyclocross and road racing

The Glycolytic energy system turns out to be a good system to produce big amounts of energy quickly (=high power). This energy system burns carbohydrates: it turns glucose into lactate. While doing so, it creates energy (anaerobically). The more active this energy system is, the more lactate it produces. Therefore, the maximal lactate production flux (VLamax) of a rider tells us something about the maximum ability to produce energy or power via the glycolytic energy system. In summary: a high VLamax is one important performance parameter that enables cyclocross riders to be explosive.

The Glycolytic system prepares the carbohydrates to fuel the Aerobic system and produces energy in doing so.

However, a high VLamax also comes at a price. If you are a sports coach or an athlete, you’ve probably experienced that a sprinter is not going to win a marathon, and a Tour de France winner will not win a bunch sprint. (Learn more about VLamax via our free whitepaper).

“In November, my VLamax was too high” – Wout van Aert (coached using INSCYD since 2017)

VLamax plays a role in this phenomenon because an increase in VLamax will increase the amount of carbohydrates burned (limited source of fuel) and therefore decrease the amount of fat burned (unlimited source of fuel), all other things being equal. In summary: a high VLamax means that more carbohydrates (a limited source of energy) are burned quickly.

When VLamax decreases (dashed line), an athlete will burn less carbohydrates (red line) and more fat (green line). When VLamax increases (solid line), an athlete will burn more carbohydrates and less fat, all other things being equal.

For a relatively short cyclocross race this might not be a huge problem, as Van Aert explains. However, when you burn all your carbohydrates in the first hour of a 6-hour road race, you have a serious problem.

STEP 2: test to see the athlete’s current metabolic profile

The INSCYD test showed the coaches of Team Jumbo-Visma (official partner of INSCYD) that the VLamax of Wout van Aert was too high to properly switch from cyclocross season to road cycling. Here is what Wout has to say about it:

Play Video about Wout van Aert - My VLamax was a little bit too high

At first it might sound strange to decrease the activity of an energy system. But lowering the VLamax immediately decreases the amount of carbohydrates burned during any exercise intensity. Or as Van Aert says:

“Lowering VLamax keeps my sugars (carbohydrates) for the final, so I don’t waste them already in the beginning.”

A decrease in VLamax will also increase the Anaerobic Threshold (FTP), all other things being equal. Van Aert explains how he already noticed that his high VLamax had a positive effect on peak power, but a negative effect on a high steady pace:

Play Video about Wout van Aert - High peak performance, low steady pace

It goes beyond this blog to dive into the theoretical and practical details of VLamax . However, if you want to know how VLamax plays a key role in coaching successful athletes, than make sure you read our free VLamax whitepaper.

STEP 3: create a training program that brings the athlete’s profile closer to the race demands

Once the training goal is clear, there are often several ways to achieve this goal. Get in touch with your local INSCYD coach or test center so they can help you to train your optimal VLamax . Always keep in mind that there is an optimal VLamax for every race. Winning a race often requires a high power attack or sprint. Just because someone with a very high VLamax could benefit from decreasing it, does not mean everybody should aim for the lowest VLamax possible! On the contrary: you need a minimum VLamax to win a race!

Here’s an example of how Wout van Aert implemented workouts that target a decrease in VLamax.

Play Video about Wout van Aert - FatMax training

How Team Jumbo Visma uses INSCYD

Learn more about how Team Jumbo Visma uses INSCYD to create better training programs via our webinar recording. In this webinar, Mathieu Heijboer (Head of Performance at World Tour Cycling Team Jumbo-Visma) gives you insights into the specific trainings for GC riders and Sprinters. You can watch the video now, or receive an email with a free link to watch it later.


For Wout van Aert, getting ready for long road races after cyclocross season meant he needed to decrease his VLamax. In practice, he used FatMax workouts to create the desired effect. That of course does not mean all riders should decrease their VLamax with FatMax workouts. We recommend coaches to walk through the 3 steps that we mentioned before jumping into conclusions:

  • 1: Know the race demands
  • 2: Get to know the current metabolic profile of your athlete via a test
  • 3: Create a training program that brings the athletes profile closer to the race demands

The INSCYD education helps coaches to better understand the race demands and create training programs that bring the athlete’s metabolic profile closer to the race demands. The INSCYD software helps coaches to create a metabolic profile of their athlete. Performance tests (e.g., lactate-, remote power-only- and/or spirometry tests) play an important role here. Let’s listen once more what Van Aert has to say about this.

Play Video about Wout van Aert - about INSCYD

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