Men’s Health did a great piece on working out when when you only have limited time to spare.  Their program utilizes resistance training to boost your resting calorie burn for up to 72 hours after your workout has finished. I’ve tried this workout over the past couple weeks to supplement my P90X2 workouts, and in only 15 mins, you do work quite a bit.

GIVE US 15 MINUTES AND WE’LL TRANSFORM YOUR BODY. Don’t have 15 to spare? Baloney, Facebook friend. The Nielsen Company says the average U.S. Facebook user spends almost 6 1/2 hours a month on the site. Guess how much time that works out to a day? Nearly 15 minutes. It’s time to edit your profile.

According to a recent study in the European Journal of Applied Physiology, 15 minutes of resistance training can elevate your resting energy expenditure for 72 hours after exercise just as effectively as 35 minutes can. That means you’ll burn off your gut and build muscle faster than you ever thought possible.

Even the most prolific poster can do it. Now there’s a new tool to help make the excuses harder to muster: The Men’s Health Big Book of 15-Minute Workouts is available this month. And on these pages you’ll find two workouts from the book—a metabolic circuit for trimming down, and a sports-specific program to prep you for snow season. Ready? This won’t take long.

15-Minute Ski and Snowboard Workout

Anyone who’s ever experienced rubbery legs after a full day on the slopes knows that skiing and snowboarding demand lower-body power like almost nothing else. Your legs are shock absorbers working with your core as you bound, hop, and carve your way down the mountain. Whether you board or ski, this workout can give you strong leg muscles and endurance to stay in control through the day’s last run.

Do the routine as a circuit, performing the prescribed number of reps for each move and then moving to the next without resting. Then rest 1 minute after you complete the circuit. Repeat, doing a total of three full circuits.

Drop lunge

A.   Using an overhand grip, hold a barbell on your shoulders behind your neck. Stand with your feet even and about hip-width apart. This is the starting position.

B.   Step back with your right foot so your right leg crosses behind your left. Try to reach as far back and as wide as possible as you sink into a deep lunge. Descend until your back knee nearly touches the floor, and then immediately drive upward to return to the starting position. Complete all your reps and repeat, this time stepping back with your left foot.

REPS 8 to 10 with each leg

Bosu medicine-ball twist

A.   Stand on the flat side of a Bosu in an athletic stance with a slight bend in your knees and hips. Hold a medicine ball at chest level with your arms straight in front of you. This is the starting position.

B.   Keeping your hips forward and using only your core, rotate your upper body as far to the left as possible.

C.   Return to the starting position, and rotate your upper body as far to the right as possible. That’s 1 rep.

REPS 5 to 8

Bosu jump

A.   Balance on the rounded side of a Bosu in an athletic stance. Brace your core and bend your knees.

B.   Explode up, raising your arms to gain height, and rotate your body counterclockwise 180 degrees. As soon as you land, bend your knees and jump, again rotating counterclockwise 180 degrees, back to the starting position. That’s 1 rep.

REPS 5 counterclockwise and 5 clockwise

Ski hop

A.   Hold a pair of light dumbbells with your palms facing in and arms straight. Stand with your feet hip-width apart in front of a sturdy box or step that’s about 18 inches high. Now squat until your thighs are about 45 degrees to the floor. This is the starting position.

B.   Press your feet into the floor and then swing your arms up as you explosively jump onto the box. The weights should end up near your shoulders.

C.   Immediately push off to jump down backward. Land softly on the balls of your feet, return to the starting position, and repeat.

REPS 20

Lateral medicine-ball hop

A.   Standing with your feet together, hold a medicine ball in front of your chest. Bound laterally to your right. When your right foot hits the floor, bend that knee and bend at the waist to move the ball down to the outside of your right foot.

B.   Straighten your body and repeat to the left side.

REPS 5 to 6 to each side

15-Minute Fast and Furious Total-Body Dumbbell Blast

This old-school dumbbell routine builds muscle and melts unwanted flab the old-fashioned way—hard work, no rest. Do this four-exercise circuit with no break between exercises. After completing a circuit, rest for 90 seconds before doing it again. Do three complete circuits.

Incline bench press

A.   Grab a pair of dumbbells and lie on your back on a bench set to a low incline (15 to 30 degrees). Lift the dumbbells up to arm’s length so they’re over your chin, and hold them with your palms turned toward your feet (thumbs facing each other).
B.   Slowly lower the weights to your upper chest, pause, and push them back up over your chin.
REPS: 10 to 12

One-arm snatch

A.    Hold a dumbbell in your right hand using an overhand grip. With your feet shoulder-width apart, bend your knees and place the dumbbell on the floor.
B.    Perform a high pull: In one explosive movement, straighten your legs and hips while bending your elbow to pull the dumbbell upward.
C.    At the dumbbell’s highest point, drop your hips and “catch” the weight by rotating your wrist under the dumbbell. Quickly straighten your arm so the dumbbell is now over the top of your shoulder. Complete all your reps, and then repeat with the dumbbell in your left hand.
REPS: Do 10 with each arm.

Seated calf raise

A.    Place a step in front of a bench, grab a pair of dumbbells, and sit down. Set the balls of both feet on the step, and hold a dumbbell vertically on each knee. Lower both heels as far as you can without touching the floor.
B.    Push off the balls of your feet and lift your heels as high as you can. Pause and repeat.
REPS: 10 to 12

Chest-supported row

A.    Grab a pair of dumbbells and lie chest down on an adjustable bench set to a low incline. Let the dumbbells hang at arm’s length from your shoulders, your palms facing each other.
B.    Without moving your torso, pull the weights to your sides. Pause, lower, and repeat.
REPS: 10 to 12

http://www.menshealth.com/fitness/15-minute-muscles