Durability — sometimes called fatigue resistance — is the newest performance metric to enter the cycling mainstream. The published research, particularly Maunder, Hopker and others between 2022 and 2025, has formalised what World Tour coaches have understood for years: a rider's 20-minute FTP fresh tells you a lot about their ceiling, but says little about what they can hold after 2,500 kJ of work. Pogačar's late-stage attacks aren't because his fresh FTP is higher than the bunch's. They're because his durability is.
The mechanism is mostly mitochondrial. After hours of riding, cellular glycogen falls, fuel oxidation slows, and the muscle's capacity to sustain high power degrades. The rider with more mitochondrial density and better fuel-oxidation flexibility maintains a higher percentage of fresh power deeper into the ride. John Wakefield has broken this down on the podcast: the work that builds durability is mostly the unsexy stuff — long zone 2, fueled rides, with strategic harder efforts placed late.
The training that builds durability isn't separate from a normal training week — it's an emphasis layered on top. Three patterns work. First, long zone 2 rides extended past three hours with the last 30-45 minutes lifting to upper tempo or threshold. Second, intervals deliberately programmed late in sessions when you're already cooked — the classic Wakefield 'finish strong' structure. Third, back-to-back weekend long rides one weekend a month, fueled appropriately. The Lorang/Wakefield Bora-Hansgrohe protocol Roadman has covered uses all three.
Fueling is the part most amateurs miss. Durability isn't built on under-fueled rides — those just teach the body to crater earlier. The published evidence and the World Tour practice line up: 70-100g of carbohydrate per hour on long rides is the protocol that allows the durability work to actually happen. Under-fuel and you bonk; over-fuel modestly and the gut adapts. The 'gut training' literature is now consensus inside cycling — the gut is a trainable organ, and durability work depends on it.
How to know it's working: your normalised power on long rides starts holding closer to your average power. Your final hour climbing power stops collapsing relative to your first hour. Your 20-minute FTP measured fresh might not move much, but your 20-minute power three hours into a sportive lifts noticeably. Track durability percentages — the ratio of fresh-versus-fatigued power across known efforts — over a season, not a session.