Ben Healy's 42km Solo Attack: How to Train for Above-Threshold Efforts

On Stage 6 of the 2025 Tour de France, Ben Healy launched a solo attack with 42.6 kilometers remaining. He rode alone into Dijon, holding off a chasing peloton that included every major GC team, to win the stage and pull on the yellow jersey — the first Irish rider to wear it since Stephen Roche in 1987.

It was a performance defined by sustained above-threshold power, intelligent pacing, and the precise management of an energy reserve that most cyclists have never thought about: W'bal.

What a 42km Solo Breakaway Demands

A breakaway of this length is not a time trial. A time trialist rides at threshold — the maximum sustainable power for the duration. A solo breakaway rider must ride above threshold because the peloton behind is sharing the workload while the solo rider fights the wind alone.

Healy needed to sustain approximately 105–110% of his FTP for over an hour. At that intensity, the body is producing lactate faster than it can clear it. Glycogen depletion accelerates. The anaerobic energy reserve — W' (W prime) — is being steadily consumed.

The race within the race was between Healy's W'bal draining toward zero and the finish line arriving before it got there.

Understanding W'bal: Your Above-Threshold Battery

W' (pronounced “W prime”) is the finite amount of work you can perform above your Critical Power (CP), which is closely related to FTP. Think of it as a battery that charges when you ride below threshold and discharges when you ride above it.

When W'bal reaches zero, you are done. You cannot sustain power above threshold any longer. In practical terms, this is the moment you crack — when the legs stop responding to what your brain is telling them to do.

Healy's genius on Stage 6 was pacing his effort so that his W'bal never fully depleted before the finish. He modulated his power constantly — pushing harder on rises where the peloton would slow, easing slightly on descents where aerodynamic gains allowed brief recovery. This micro-pacing extended his W'bal across a distance that would have destroyed a less-disciplined rider.

The Physiology of Sustained Supra-Threshold Riding

Riding above FTP engages several energy systems simultaneously, and the interplay between them determines how long you can hold the effort.

Aerobic System (The Foundation)

Even at 105–110% of FTP, the aerobic system still provides the vast majority of energy — roughly 85–90% of total ATP production. This is why aerobic base fitness matters so much for above-threshold performance. A rider with a higher FTP and better aerobic capacity can sustain higher absolute power in the supra-threshold zone because their aerobic system shoulders a larger share of the load.

Glycolytic System (The Burn)

The remaining 10–15% comes from anaerobic glycolysis, which produces ATP rapidly but generates lactate as a byproduct. At above-threshold intensity, lactate accumulation exceeds clearance rate, and blood lactate rises progressively. This is what creates the burning sensation in your legs and the progressive sense that you cannot maintain the effort.

Lactate Shuttle (The Buffer)

Trained athletes clear lactate more efficiently than untrained ones. Lactate produced in fast-twitch fibers is shuttled to slow-twitch fibers and the heart, where it is used as fuel. A well-developed aerobic base increases lactate clearance capacity, effectively extending the time you can ride above threshold.

This is one reason why base training — months of Zone 2 riding — improves above-threshold performance despite never training at those intensities. The aerobic engine built during base work clears lactate faster, which directly extends W'bal.

How to Train for Above-Threshold Efforts

You do not need to be a Tour de France winner to benefit from above-threshold training. Any cyclist who races, does group rides, or needs to hold pace on climbs will benefit from a larger W' and better pacing skills. Here are the key workout types.

1. Over-Under Intervals

Over-unders are the gold standard for training lactate clearance and above-threshold tolerance. They alternate between power just above FTP (“over”) and power just below FTP (“under”), teaching your body to produce and clear lactate simultaneously.

• Beginner protocol: 3 × 9 minutes. Each block: 3 min at 95% FTP, 2 min at 105% FTP, 2 min at 95% FTP, 2 min at 105% FTP. 5 min recovery between blocks.
• Advanced protocol: 4 × 12 minutes. Each block: 2 min at 95% FTP, 2 min at 108% FTP, alternating. 4 min recovery between blocks.

The key is that the “under” portions are not true recovery — they are still at threshold, forcing your body to clear lactate while still working hard. This is the specific adaptation Healy would have trained extensively.

2. Sustained Threshold Blocks at 105–110% FTP

These intervals develop your ability to hold power above threshold for extended periods. They simulate the demands of a breakaway, a long climb, or bridging to a group.

• Protocol: 3–4 × 8 minutes at 105–110% FTP, with 6–8 minutes recovery between intervals.
• Progression: Start at 105% FTP for 6-minute intervals. Over 4–6 weeks, increase either the interval length (to 10 minutes) or the intensity (to 110% FTP), not both simultaneously.

3. VO2max Intervals for W' Development

Short, high-intensity intervals at 115–130% of FTP develop your VO2max and expand your W' reservoir. A larger W' means more total energy available for above-threshold efforts.

• Classic VO2max protocol: 5–6 × 4 minutes at 115–120% FTP, with 4 minutes recovery.
• 30/30 intervals: 10–15 × 30 seconds at 130% FTP, 30 seconds at 50% FTP. These accumulate significant time at VO2max while managing fatigue through micro-recovery.

4. Race-Simulation Rides

Once a week, include a ride that simulates the demands of your target event. For breakaway training, this means riding solo at 102–108% FTP for progressively longer durations: start with 20 minutes, build to 40 minutes over several weeks.

The psychological component matters as much as the physical one. Racing above threshold is uncomfortable by definition. You need to practice tolerating the discomfort and trusting your pacing when every signal from your body says slow down.

Pacing: The Breakaway Rider's Secret Weapon

Healy did not ride at a constant power for 42 kilometers. No one does. The art of a solo breakaway — and of any sustained above-threshold effort — is intelligent pacing.

The Variable Power Strategy

On uphills, aerodynamic drag decreases and gravitational resistance increases. Pushing slightly harder on climbs costs less in total energy than pushing harder on flats, because the time saved per watt is greater at lower speeds. Healy would have pushed to 110–115% FTP on rises while recovering to 95–100% FTP on descents and flat sections.

Monitor Your W'bal in Real Time

Some bike computers can display a real-time estimate of your W'bal during a ride. This is a game-changer for pacing above-threshold efforts. If your W'bal is dropping rapidly, ease off. If it is stable, you can push slightly harder. The goal is to arrive at the finish with W'bal as close to zero as possible — that means you used everything you had without cracking.

Paincave tracks your W'bal across every ride, showing you exactly when you approached depletion and how your W' reservoir has changed over time. This data lets you calibrate your pacing strategy for future efforts.

Applying This to Your Riding

You do not need to ride 42 kilometers solo off the front of the Tour de France to benefit from above-threshold training. These skills apply to everyday cycling situations.

• Bridging to a group — You need 2–3 minutes at 110–115% FTP to close a gap, then recover back to group pace. Over-under training prepares you for exactly this.
• Climbing — Most climbs take 10–30 minutes at or above threshold. Sustained supra-threshold blocks teach you to hold power on the gradient.
• Criterium racing — Crits demand repeated short efforts above threshold with brief recovery. VO2max intervals and 30/30s are directly applicable.
• Sportive finishing kicks — The last 5 km of a gran fondo when you want to beat your time requires digging into your W' reserve. Knowing how much you have left is the difference between finishing strong and blowing up.

Healy's Stage 6 was a masterclass in above-threshold riding. But the principles behind it — W'bal management, lactate clearance, variable pacing — are tools that every cyclist can develop and use.