Everesting - i.e. riding up and down (then back back up etc) a climb until cyclists complete 8,848m of ascending - first coined by the Australian Hells 500 club - is not for the faint-hearted at the best of times.
But just under 11 hours on a stationary bike is quite possibly taking things to another level.
For those playing at home, that's eight and a bit times up and down the virtual Alpe du Zwift covering a total of 211km.
"Just Everested, vEverested, whatever you want to call it," he posted on Instagram. "We had the idea a couple of weeks back, but waited til we knew it’d be bad weather outside.
"I take my hat off to anyone who’s completed it in whatever capacity, it was grim."
Cav completed the challenge virtually with Team Ineos rider Luke Rowe, the pair following in the self-isolation footsteps of Trek-Segafredo's Giulio Ciccone who notched up a whopping 10,397m (and 254km) in 11 hours and 19 minutes last month.
"I was cooked, completely empty!" Ciccone said afer his ride. "I lost 2.1kg and consumed about 9,000 calories.
"I've never felt as bad, even after cracking in a race in the cold and rain."
"Everesting was something I'd wanted to try to do...out on the road. I'd never thought about doing on the home trainer because it's probably twice as tiring."
The coronavirus pandemic has produced a number of epic rides by pro cyclists making up for a lack of racing and are either in full lockdown or self-isolation.
Geraint Thomas completed three 12-hour shifts on Zwift for NHS Charities, Laurens De Vreese pumped out 368km in just over 11 hours, and Remco Evenepoel rode up the famous Tour of Flanders Muur van Geraardsbergen climb 50 times notching up 5,145m of climbing in the process.
vEveresting is an official challenge in Zwift with an achievement unlock, the reward a lighter bike. It does not need to be tackled in one go.