Just watching the riders of the Giro d'Italia battle against the gradient up the Monte Zoncolan was enough to feel exhausted, let alone those riding it.
Jan Tratnik (Bahrain-Victorious) zigzagged across the road as he tried in vain to claw back Lorenzo Fortunato (EOLO-Kometa), who held on to take the stage 14 win, while Egan Bernal (Ineos Grenadiers) took more time on his general classification rivals.
Following the stage, and after picking themselves up off the floor, some riders have shared their data on Strava, upturning the previous top 10 leaderboards on the segments up to the summit.
Over the final 3km, the steepest part of the climb, the average gradient is over 12 per cent but reaches an eye-watering maximum of 27 per cent.
Bahrain-Victorious' Damiano Caruso now holds the KOM up to the summit from the Sutrio side by 19 seconds over Romain Bardet, the Italian one of the first of the GC contenders to cross the line after Bernal and Simon Yates had jumped from the group, and now moves up to third in the general classification.
Caruso averaged 14.3km/h over these final few kilometres, but his average speed up the final 'Muro finale' segment was only 10.8km/h - the road must have felt like it was almost vertical - and his average power is estimated to have been 415W.
BikeExchange's Nick Schultz also posted his heart rate data, averaging 166bpm over the final few kilometres.
The stage winner Fortunato showed his victory wasn't only down to the head start he'd given himself from his presence in the breakaway, as he posted times quick enough to get inside the top five on the Strava leaderboards.
Of course, not all riders have posted their data, and the likes of Bernal and Yates would likely have the top two times had they decided to share the numbers behind their rides.
Climbing Records, however, estimate that Bernal has set the fastest-ever time on this side of the Zoncolan, riding it in 40-02 at an average speed of 19.63km/h.
This is estimated to be 1-26 quicker than the previous best time of Gilberto Simoni, who won the Zoncolan stage at the 2003 Giro.
Thank you for reading 20 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1