Roux describes the uncategorised ascent as ‘a small climb, not so hard but a good warm-up for the legs’ before a short, fast descent towards Embrun and the Serre-Ponçon lake. It’s important on these opening climbs to pace yourself, Cotty says. “It’s about not burning too many matches, too soon,” he warns. “Hold everything back… this is just a warm-up climb, don’t push too hard.”

The Côte de Demoiselles Coiffées follows and is the ‘first difficult climb of the day’, according to Roux. It’s a relatively tough climb, he says, with some steeper sections as the road rises to 1024m – though Etape riders will be rewarded with spectacular views back over the Serre-Ponçon lake. “Enjoy the spectacular scenery but be sure to eat and drink enough,” Roux says. “It will be key for what follows.” Cotty agrees, emphasising the importance of staying well fuelled through the early part of the ride.

The top of the Col de Vars marks 129km on the clock and a 19km descent follows, with riders losing more than 1,000m in elevation before arriving at Guillestre. “You’ve got to be careful [on the descent],” Cotty says. “Some of those bends come up really quick – so pay attention. Try and relax, recover.”

The Col d’Izoard awaits from here but first Etape riders face 16km kilometres in the valley on a false flat, where the gradient hovers at around three or four per cent. “You really need to work in a little group,” Cotty says. “Don’t ride it on your own.” Roux recommends using the valley road to re-fuel ahead of the Col d’Izoard. “Be sure to use this section to eat and drink,” he says.

The Col d’Izoard, which has been used in the Tour de France 35 times to date, is made famous by the Casse Déserte and its barren, weathered and dramatic scree slopes. Etape riders will enter the Casse Déserte with three kilometres remaining.

“It feels like you’re swallowed up with these pinnacles of weathered rock,” Cotty says. “It’s really impossible not to feel humbled in such a landscape. It’s such an amazing way to finish. Then the gradient kicks up again. It hits you hard, nine or nine-and-a-half per cent all the way to the top.”

The final kilometre is the steepest, with the average gradient now up to ten per cent, and with 178km in the legs, it will be a battle of man and machine against the mountains for every Etape rider – but, as they cross the finish line at 2,360m, they are sure to feel the same ‘total and pure joy’ as Roux and Cotty after what is set to be another classic edition of the Etape du Tour.