The Third Week
As the Tour de France heads into its third week, you'll start to see cracks forming in the day-to-day performance of some of the racers. The physical and mental demands of the race take their toll, not in one dramatic blowup, but in fractions of a watt per kilo, stage after stage. The guys still producing their week-one numbers in week three aren't necessarily the fittest. They're the most durable.
Durability has become one of the more useful words in endurance science over the past few years. Researchers define it as when, and to what extent, your physiological markers decline over the course of a long ride or race. Power output and efficiency drop, heart rate drifts, and rate of perceived exertion climbs. In other words: durability measures how much of your fresh-leg fitness you have when you're not fresh anymore.
If this sounds familiar, it should — we've been circling around it the last two weeks without naming it. Cramping, we said, is mostly a fatigue problem: the neuromuscular signal that tells a muscle when to fire and when to relax gets noisy as fatigue builds, and things lock up. That's durability failing in your wiring. Grit, last week, was about holding your standard when you're depleted and nobody's making you. That's durability's mental half — the will to keep pushing a body that's already given a lot to give a little more.
The useful part is that durability is highly trainable, and it doesn't require a bigger engine. It requires practicing being fatigued, deliberately: pedaling hard when pedaling already feels hard.
You don't need to survive a 3-week Grand Tour to benefit from training your durability — you just need to occasionally practice riding hard on less-than-fresh legs.
Here’s how to work on building durability during your normal training weeks:
Put your intensity at the end of long rides instead of the beginning, so your legs are doing hard efforts on fatigued legs, not fresh ones.
Stack consecutive training days to take advantage of accumulating fatigue. Don't ride yourself into the ground, but push the limits of your day-to-day endurance to build physical and mental adaptations and resilience.
And when you test yourself, don't just test your fresh number — test what you can still hold after two or three hours in the saddle. That number, more than your fresh FTP, is what durability is all about.
See you next week,
Steve