It’s August and, if you’ve caught a case of CX fever, this is one of the most anticipated times of the entire season. Whether you’ve planned your season completely around CX, or whether you’re looking to extend your racing season after a full season of road/MTB, CX demands a specific training focus that is ideally tackled using Xert’s Workouts feature.

In the northern hemisphere, most of us have been putting in lots of time on the bike throughout the spring and summer. Therefore, in general our overall fitness and aerobic capacity is already at a high level. Long rides of 4 to 5 hours are not uncommon, and our Threshold Power (TP) is likely also fairly high and stable.

This all changes with the requirements of CX season. Besides the obvious differences in technical demands (barriers, varied terrain, very low pressure tires, cornering, etc.) and in the need to dismount and run, the physical requirements for success also contrast sharply with many forms of road racing and especially time trialing.

The biggest physical demands of CX includes:

  • The massive surge off the line from a standing start, with power outputs that nearly rival that of a road race sprint finish.
  • The ability to repeatedly surge from an already-high sustained power output and fatigue buildup.
  • Surges are generally extremely short – 3-6 s in duration.
  • Neuromuscular differences in accelerating from low speed/cadence and in a relatively high gear.
  • Usually accelerating while seated to maintain traction and a lower centre of gravity.

The Cheung CX Series

Xert’s Workouts, featuring both traditional and Smart workouts, already offer a comprehensive library of workouts catering to cyclists of all interests. But to celebrate all things CX, we are proud to introduce a CX Workout Series designed by Dr. Stephen Cheung, Baron Biosystem’s Chief Sport Scientist. These are all available easily in Xert Workouts by searching “Cheung CX.”

“CX season is my favourite time of the cycling year, and I’m very pleased to share some of my favourite workouts with the Xert community. I’ve designed them to replicate the challenges that are highly specific to CX, notably the sustained fatigue and repeated surges. Xert’s unique workout capabilities allowed a high level of specificity that really enhances the ability to customize training.”

Hot Laps

As an example, “Hot Laps” concentrate on that intense first ½ to ¾ lap of a CX race. “This is my own personal weakness,” confesses Cheung, “so I had high motivation to develop this workout.”


Each interval starts with an intensely fatiguing sprint off the line, with a Xert Stress Score Rate (XSSR) of 300 lasting until Maximal Power Available (MPA) drops to 85% of max. Only a very slight recovery in MPA is permitted before 6×20 s surges with 20 s of recovery still at high effort.

Immediately upon full MPA recovery, another starting sprint is thrown in. This entire pattern is repeated three times, for a total of 3 hot laps and 3 additional starting sprints. “It’s hard to overstate the importance of a fast start in CX, and that is what this workout is all about,” notes Cheung.

Breakaway Specialists and Rouleurs

The new Cheung CX Series are not the only Xert Workouts with relevance to CX. “In analysing prior race data, the Focus for my races is typically towards those of the Breakaway Specialist (5 min power) and Rouleur (6 min) profiles. The specific nature of the course (weather, the number of dismounts, etc.) can of course greatly vary the specific profile,” says Cheung “so the existing Workouts with this focus targets many of the same demands for me.”

As an example, the “Positive Split Micros” with repeated efforts to drop MPA to 80-89% can be a great way to get a large dose of High Intensity strain. “To make things even more specific to CX, do this workout seated and in a gear or two harder than you typically might during road training,” suggests Cheung. “This replicates the challenge of accelerating that is a staple of CX.”

How to Use the Workouts

With CX season approaching, there are a lot of things to consider and plan, and Xert can be the partner to your best muddy season yet! It is important to set aside days specifically for technical practice and running. But August and September is when you should be converting all of that endurance, aerobic capacity and threshold power into High Intensity Energy that is sustained and repeatable.


Here is the Cheung CX – Stomping Tom, another example of a workout that replicates the repeated high surges, sustained fatigue, and then more surges inherent to CX. “For this workout, the emphasis – besides survival – should also be on using a harder gear than normal and staying seated to really stomp and drive the pedals,” notes Cheung.

Look back through your own prior CX race data to see what Focus they tend towards, then gear your training appropriately. At the same time, do not completely neglect your Threshold Power and endurance ability. That is where workouts like the 2×30 and 3×30 Over Unders in the Cheung CX Series, done 1-2x/week, can be highly effective, providing lots of Low Intensity strain but still forcing you to react to changes in power output.

Six workouts are currently in the series, with more to come as the inspiration hits us. Let us know on Facebook how these workouts are treating you and to recommend other CX workout possibilities!

Free 30-day trials are available when you register.  The company has published a number of blogs, videos and FAQs on their website to help athletes, coaches and sport scientists become familiar with the new concepts.