Many years ago I was stupid enough to be on Strava, when one day J noticed I was ranked 11th on a local segment. That was very decent, considering that would have been set on a sportive commuter bike with mudguards and rucksack.
So for a few days I paid attention and poured on a bit of power, just got a feel for what was required and when.
And then on a rest day I attacked it on my Felt roadie.
I got a good run in, took the corner well to set up a nice fast entry, and then hammered it like id never done before in my life. I got past the end point, smacked the power for another second of so to be sure, and then backed off.
And thats when I nearly fainted. I manged to pull up safely and take a minute or two to gather myself and was OK to carry on gingerly home, but that really frightened my and I deleted my Strava account that evening so I wouldn't be tempted to do something so stupid again.
I did get the KoM, which was a helluva achievement for a then 250lb bodybuilder in his early 40s, but the cost could have been injury or death if I'd fainted while on the move or pushed myself into a heart attack.
This guy is a gold plated prat. We had a name for road users like him in the dibble - Organ Donors.