Lots of exercise programs this time of year claim to get you in the best shape of your life. But how many can claim to get some of the top trainers in L.A., thousands of badass cops, and a large number of Navy SEALs in the best shape of their lives?

Such are the specs for the fitness plan you'll find on the next two pages. Adapted from a program called "CrossFit," which has developed a vast underground following on the Web, the plan is not only scarily effective, it's the most time-efficient workout you've ever seen. This double espresso of a cross-training regimen takes familiar functional multijoint exercises such as squats, pull-ups, and medicine ball throws, preaches perfect form and full range of motion, tosses in bursts of cardio, and has you crank up the intensity by clocking it all with a stopwatch. Most days you'll blitz through it in 20 minutes or less. The world record for one benchmark drill (number one on the next page) is seven minutes, 35 seconds.

Easy, right? Well, as you're standing there, ready to vomit, easy probably won't be the first word that springs to mind. So amazing will do.

Your 20-Minute Plan

CrossFit, the white-hot, California-based exercise program that inspired this plan, is fast, intense -- and a stickler for form. Each day, do the drill indicated, and pay special attention to the signature move shown. Every fourth day, take the day off. When you get to 10, start cycling back through from one and repeat for a month or until your pickup hoops opponents beg you to stop.

WORKOUT 1
3 rounds, for time, of:
1/4-mile run,
21 35-lb dumbbell swings
12 pull-ups. If you can't do 12, break them up into doable sets.

Dumbbell Swings
Hold a 35-lb weight with two hands, and drop into a squat, then explode upward through your heels until your hips lock in a standing position, the momentum driving the weight up over your head. Then drop into a squat and repeat.

WORKOUT 2
Do as many rounds as possible in 15 minutes of:
3 pull-ups
6 push-ups
9 squats

Squats
Keep your head up, back arched, arms outstretched, and heels down as you lower your butt to within a foot of the floor. You can place a medicine ball under your butt and touch it to make sure you don't cheat.

WORKOUT 3
10 rounds, for time, in reps of 10, 9, 8, 7, 6, 5, 4, 3, 2, and 1 of:
body-weight dead lifts (i.e., if you weigh 180, lift 180)
3/4-body-weight bench presses

Dead Lifts
A perfectly performed dead lift gives you unmatched full-body strength. Squat down to the barbell at your feet. With arms locked, grab the bar and pull it off the ground as you stand up straight in a smooth, controlled motion.

WORKOUT 4
4 rounds, for time, of:
1/4-mile run
5 box jumps (on and back off a 20-in step)
15 wall balls (with 15-lb ball)

Wall Balls
Stand 18 ins from a wall with a 15-lb medicine ball under your chin. Squat, then explode up, throwing the ball about 10 feet up the wall. Catch under your chin, descend, and repeat.

WORKOUT 5
3 rounds, for time, of:
1/2-mile run
40 good mornings (with 45-lb barbell)
40 sit-ups

Good Mornings
This sub for a back extension has you bend at the waist with your head up, back straight, and an unweighted 45-lb bar across your shoulders.

WORKOUT 6
Do for time, resting as needed:
50 pull-ups
60 ring push-ups
70 sit-ups
80 squats

Ring Push-Ups
Doing push-ups on unstable rings requires way more effort than doing them on the floor. Attach gymnastics rings or a pair of cable machine handles, as shown here, to a pull-up bar, and hang within 1 to 6 ins of the ground. Kneel on the ground in the pre-push-up position, hold the rings steady, and do your push-ups.

WORKOUT 7
For time, 3 rounds in reps of 21, 15, and 9 of:
thrusters (with 65-lb bar)
pull-ups. Switch pull-up grips between over- and underhand.

Thrusters
Like wall balls, except you use a bar, not a ball -- and don't let go. Hold the bar with hands about a foot apart, lower into a squat, then thrust upward.

WORKOUT 8
7 rounds, for time, in reps of 21, 18, 15, 12, 9, 6, and 3 of:
dumbbell swings (with 35-lb dumbbell)
ball slams (with 20-lb ball)

Ball Slams
Hold a 20-lb nonbouncing medicine ball overhead, back arched. In one motion, slam the ball to the ground between your knees as you drop into a squat, grab the ball, explode up to the start, and repeat.

WORKOUT 9
For time, do:
40 burpees
50 thrusters (with 45-lb barbell)
30 pull-ups

Burpees
Great for developing quickness and agility. Starting from a standing position, squat down with your hands on the ground in front of you and fling your legs backward into the lowered push-up position. Jump back up to your feet, then leap into the air.

WORKOUT 10
3 rounds, for time, in reps of 21, 15, and 9 of:
135-lb dead lifts
handstand push-ups. Sub in shoulder presses as needed.

Handstand Push-Ups
Lean over and touch your hands to the floor a foot from a wall. Throw one leg into the air, and push off with the other leg. With both feet touching the wall, lock your arms until you're stable, then lower until your nose is 2 ins from the floor. Then push up until locked again.