So what does that mean, exactly?
According to Alyssa Ages, a certified personal trainer, CrossFitter, and founder of BeFit Marketing, the workout itself consists of "a bunch of different functional-fitness exercises, done quickly, for a set period of time and a set format."
Functional exercises are ones that mimic real-life movements, and usually require little or no equipment, like burpees, push-ups, and sit-ups, as well as movements with barbells, dumbbells, kettlebells, jump ropes, pull-up bars, rings, and medicine balls.
"I'd call it both [an exercise regimen and a sport], but the best term I've heard for it is 'competitive exercise,'" Ages says.
"The saying in CrossFit is that we don't use machines, we are the machines," adds Amy "Pistol" Mandelbaum, owner and head coach of CrossFit Westport. "We use barbells, dumbbells, rowers, kettlebells, and 'rigs' for pull-ups. A CrossFit box is like Tinkertoys for adults. Everything is mobile and can be configured to accommodate different movements. Many exercises are bodyweight-oriented, such as burpees, push-ups, jump rope, pull-ups, running, and more."