Why the Cobbled Classics Hurt — and How the Pros Train for Them

Races like Paris-Roubaix and the Tour of Flanders are some of the most demanding events in professional cycling. They're not just long — often lasting over six hours — but brutally intense. Riders face relentless cobbled sectors, unpredictable weather, constant jostling for position, and the need to produce repeated high-intensity efforts. It’s a race of attrition where only the strongest and most intelligent survive.

One of the key challenges is the repeated need to surge above threshold. In a typical race, riders may have to produce 500–600 watts for 30 to 60 seconds when entering cobbled sectors, attacking, or chasing splits — and they do this over and over again throughout the day. The best riders can sustain an average of 300 to 320 watts (around 5–5.5 W/kg for climbers or puncheurs) over the entire race, with the final hour often raced at or above their functional threshold power (FTP), despite deep fatigue.

Mathieu van der Poel launches a powerful attack through the iconic Arenberg Forest sector during Paris-Roubaix (Photo: Chris Auld).

Riding on cobblestones isn’t just about pedalling hard — it’s about full-body control. The constant vibration and jarring terrain create additional neuromuscular fatigue, especially in the arms, core, and lower back. This makes upper body and trunk strength far more important than in a typical road race. Combine that with the huge energy demands — with total energy expenditure often exceeding 6,000 to 7,000 kilocalories — and you have a race that drains every part of a rider’s body. To make it harder, riders often can’t eat or drink safely during the roughest sectors, so fuelling must be timed carefully before and after the cobbles.

Mental fatigue plays a massive role as well. Riders are constantly on edge — choosing lines, reacting to crashes, and reading the race. Poor decisions or a momentary lapse in focus can cost valuable time or worse, lead to a crash or mechanical. And to top it all off, the weather can swing from freezing rain to scorching heat, adding another layer of stress and complexity to pacing, fuelling, and hydration.

Training Like a Classics Rider: Power, Pain, and Preparation

To prepare for this unique set of demands, professional riders use a mix of interval sessions and long simulation rides. For the average rider with an FTP of 200–230 watts, these sessions might look like the following:

• VO₂max Repeats: 5 x 4 minutes at 110–120% of FTP, which for a 215-watt rider would be around 235–255 watts, with equal rest between efforts. These improve your ability to produce high power under fatigue.

• Over/Unders: 2 x 20-minute blocks alternating 2 minutes at 90–95% of FTP (180–200 watts) with 1 minute at 110% (235–250 watts). This mimics the intensity changes of racing and helps with lactate clearance.

• Sweetspot + Sprints: 3 x 12–15 minutes at 88–93% of FTP (around 190–200 watts), with a 10–12 second sprint at 300+ watts every 2 minutes. This builds sustained power and explosive capacity.

• Long Rides with Intervals: 3–4 hour endurance rides on rough or mixed terrain, including short efforts of 30–60 seconds at 300+ watts on hills or into the wind every 10–15 minutes to simulate the repeated efforts of a race like Roubaix.

• Core and Upper Body Strength Training: 2–3 sessions per week focusing on core stability, lower back endurance, and grip strength — essential for comfort and control on cobbles.

  
  

Winning a cobbled classic like Paris-Roubaix requires a mix of endurance, explosive power, and extreme durability. Peak sprint power in the final kilometres can reach 1000 to 1200 watts, while short bursts of 600 to 700 watts for 30 seconds to a minute are required repeatedly throughout the race. Sustained efforts at 300 watts or more for over five hours, often in wet and windy conditions, separate the contenders from the rest.

For the average cyclist, these races are a masterclass in how complex and complete cycling fitness can be. If you want to replicate even a fraction of the demands, focus on building your FTP, improving your repeatability with intervals, and strengthening your core. Add some gravel or rough road rides into your routine and you’ll quickly see how different — and demanding — these legendary races really are.

Interested in unlocking your own performance potential?

Please get in touch today if you wish to determine your own physiology by way of a VO₂max or lactate threshold assessment:📧 info@edgeperformancescience.co.uk