June 13, 2026 · 5 min read

Alpe du Zwift — How to Pace an Hour-Long Climb Without Blowing Up Halfway

Alpe du Zwift is a virtual recreation of Alpe d'Huez — roughly 12.2 km and 1000 m of climbing, averaging 8.5% with sections above 12%. For most amateurs it's an hour-long effort close to threshold, and the most common mistake is starting too hard and blowing up in the second half.

How much power do you need to hold for the whole climb

For a finish time around 60 minutes, the typical target is 75–85% FTP — tempo/sweet spot range, sustainable for an hour without deep acidosis. Attempting 95–100% FTP from the gun usually ends in a significant power drop after 20–25 minutes, once muscle glycogen and lactate tolerance run out.

What power in W/kg do I need for Alpe du Zwift?

As a rough guide: 2.0–2.3 W/kg gets you close to 70–80 minutes, 2.5–2.8 W/kg lands around 55–60 minutes, and a sub-50-minute time typically requires above 3.2–3.5 W/kg — a level reserved for advanced racers.

How to distribute effort on the climb

• First 10 minutes — start 5–8% below target power to avoid excessive acidosis before your body "warms into" the threshold effort.
• Mid-section (>10% gradient sections) — accept a temporary power spike on the steepest sections, but return to target pace on gentler stretches instead of holding a fixed absolute wattage throughout.
• Last 2 km — if TSB and how you feel allow it, this is where a finishing surge belongs — pace the rest of the climb so that surge is actually possible.

Is it better to ride at constant power or adjust to the gradient?

On a real mountain climb (and its virtual recreation), riding closer to constant perceived effort (RPE) works better than rigidly fixed wattage — on the steepest sections a natural cadence drop and momentary power spike are unavoidable; the key is returning to your baseline pace quickly right after them.

Equipment and fueling prep

• Hydration — even though it's an indoor session, an hour near threshold generates real sweat losses; prepare a minimum of 500–750 ml with electrolytes.
• Carbohydrate — for 60+ minutes at this intensity, plan on 30–40 g of carbs during the effort, especially if it's part of a longer session.
• Trainer calibration — do a spin-down right before starting; a calibration error over a long threshold effort easily skews the real load up or down.

Bottom line: the key to finishing Alpe du Zwift without a power collapse is a conservative start and deliberate effort management on the steepest sections, not maximum power from the first minutes. Treat it as a 60-minute threshold session — discipline in the first half determines the result in the second.

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