Give your fitness routine a boost with this full-body workout.

If you haven't been able to do a chin-up since second grade recess (we haven't either), you'll welcome this workout. 

A favorite among pro athletes, firefighters and Marines, CrossFit is a hard-core regimen that combines strength training and conditioning for a head-to-toe overhaul.

"We specialize in not specializing," says Allison Bojarski, a trainer and operations manager for CrossFit NYC. The well-rounded routines improve endurance, tone muscles, and leave you less prone to injury.  

The first class (a freebie!) focuses on mastering squats, push-ups, and sit-ups. Take the intro as many times as you like, then graduate to The Elements Workshop ($300 for 6 sessions with no more than 6 students, followed by 2 weeks of free classes). You'll learn everything from hoisting the kettle bell to doing a deadlift. Expect to be pulling your own weight--literally--in no time.

(Worried about bulking up? Don't buy that bogus myth!)

CrossFit NYC, 25 W. 26th St., (646) 290-6005, MAP