n. A period of extreme suffering or discomfort brought on by intense physical exertion.
Also Seen As
A hundred years ago, when Robert Falcon Scott set out for Antarctica on his Terra Nova expedition, his two primary goals were scientific discovery and reaching the geographic South Pole. Arguably, though, Scott was really chasing what contemporary observers call a sufferfest. …

But perhaps the real reason to court a sufferfest — to explore or adventure, or whatever you want to call it — is that it makes a person feel alive.
—Elizabeth Weil, “The Woman Who Walked 10,000 Miles (No Exaggeration) in Three Years,” The New York Times, September 28, 2014
O'Grady, Australia's most-experienced rider, said: "It will be really, really nasty. When it's 35-plus it's hard; over 40 is downright ugly and there's no way to acclimatise for it. It's going to be a sufferfest."
—Ron Reed, “'Sufferfest' for Jayco Herald Sun Tour Stage 1 riders,” The Courier Mail (Brisbane, Australia), January 03, 2013
1999 (earliest)
Next, we go to Tour Of Redlands, so that's why I have been training down here. I've been doing 'Suffer Fest' for a month or so, getting my fitness ready for Redlands.
—Jessica Mundie, “Top riders seek Majic points,” St. Petersburg Times (Florida), February 24, 1999