Think CrossFit, Bikram yoga, and ultramarathons.
They're same-same but different to your average exercise.
Average exercise we might describe as "fun" whereas flogging yourself fitness is more about self-flagellation.
It's not just being stuck in a stinky sauna and flicked with someone else's sweat while you workout (looking at you Bikram).
Overheating, vomiting, enduring electric shocks, dehydration, bruises, cuts, kidney-failure and cardiac damage are just some of the potential risks of such high-intensity forms of fitness.
So why are people drawn to them in droves?
Some put it down to our instant gratification, go hard or go home culture.
"It's psychologically more rewarding than plodding away on a treadmill," says sports psychologist Jeremy Adams.
The physical catharsis of these types of exercise is huge. But the feel-good factor seems to lie largely in the mental benefits. A 2013 study by Australian researcher Eric Brymer found that the challenge of mind over matter - in this case our bodies - can be mentally and emotionally "transformative".
"What we're finding is that when people are feeling a loss of control, they're particularly likely to go for these high-effort things like very intense workouts because it makes them feel empowered," says study co-author Keisha Cutright.
But there is a dark side to extreme exercise.
A 2011 study by University of Queensland psychologists found that those who felt guilt in their life were more prone to punish themselves through pain.
"There is also the potential for massive injury," Adams says.
For the most part, however, getting hooked on exercise and pushing our limits here and there is healthy. "Provided we have plenty of rest, have good instruction, diets and sleep, you can have high intensity workouts," Adams says. "They give better mood benefits.
"The harder you work out, the better - to a point. If you vomit, you won't feel good."
- The Press
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