If you’re trying to flatten your stomach—in search of that mythical six-pack, or just to look like you’ve had fewer six-packs—you’re probably spending a lot of workout time on the floor.

Time to get up. “Anytime you’re on your feet, you’re getting more muscles involved because you have to stabilize yourself,” says Nick Tumminello, Baltimore-based strength coach and founder of Performance University. “The more your body is having to do, the more calories you burn.”

You’ll also reduce back and hip pain. “Your core is much more than the six-pack—it’s all of the muscles around your spine, through your back, your stomach, your hips,” Tumminello says. “In order to have a healthy spine, you need to be able to control optimal posture. And that involves getting your whole core involved.”

Stand up and give it a shot with these tips from Tumminello and Aaron Brooks, a biomechanist in the Boston area and owner of Myoforce. Add one of these strategies to your normal workout, or put them all together: Perform 1 set of 10 reps of each exercise, then move to the next. Complete the entire sequence 3 times for a fat-blasting core workout.

Drop a Dumbbell

If you’re already working with dumbbells, don’t change your routine, says Tumminello. Just eliminate one dumbbell—the offset load will force you to brace your core to keep your shoulders even. (The same concept applies to your legs: Try standing on one foot with your core slack. Before you fall, brace your abs and stand up.) Offset load works well with squats, dumbbell bench press, and deadlifts, but try these two moves to start:

Offset Dumbbell Walking Lunge

How to Do It: Stand holding a dumbbell in one hand straight down from your shoulder, palm in. Take a large step forward with one leg and descend until both knees form 90-degree angles, but your back knee does not touch the floor. Stand up by bringing your back leg up to meet your front foot. Lunge again, this time stepping forward with the other leg. Perform half of your reps with the weight in this hand, then switch hands and finish your reps.

Standing Single-Arm Shoulder Press

How to Do It: Stand holding a dumbbell in one hand at your shoulder, palm facing your head. Keeping your shoulders even, press the dumbbell straight overhead. Return to start. Complete your reps with this arm, then switch arms and repeat.

Try This at Home

You don’t need weights—or even a gym—to lose the situps and get a stronger core, faster. Try these tight core rotations from Tumminello to get cardio while you work your core. Mix them with pushups, squats, and lunges for a total body workout—no equipment needed.

Tight Core Rotations

How to Do It: Stand with your feet hip-width apart, with your arms extended in front, palms together. Brace your core. Keeping your hips square and your core engaged, rotate your upper body to one side so your arms are in line with your shoulder. Reverse quickly until your arms are in line with the other shoulder. Continue alternating as fast as you can.

Get Your Ass Into It

Your core stabilizes your spine forward and back, but also side to side, says Brooks.

“The glutes are the missing link,” he says. “Your glutes are tied to how your core fires. If you don’t train your glutes, you aren’t training the whole core.”

By strengthening the core muscles that keep you stable moving side to side, you can reduce knee and hip pain while you strengthen your glutes—allowing your core to fire how it’s supposed to. Try this strap exercise to strengthen laterally.

How to Do It: With your feet hip-width apart, wrap a strap (or buckle a belt) around your thighs slightly above the knees. Apply pressure outwardly on the belt by pressing your knees out; this will transfer weight slightly onto the outside of your feet. Hold for 20 seconds, then release and repeat.

Stop Rotating

Lots of core exercises involve rotation—the tight rotations above, the medicine ball exercise below, or the side-to-side deal Mr. T does in Rocky III.

But experts like Brooks are now recommending anti-rotation, too. What that means: When a force tries to pull you out of position—like a rope yanking you from a standing position—your core is what keeps you standing. Anti-rotation trains that.

To get a feeling for it, try this cable single-arm press from Brooks.

Cable Single-Arm Press

How to Do It: Stand with your back to a cable station, holding the handle in your right hand in front of your right shoulder, your arm bent. Stand in a staggered stance, your left foot 3 feet in front of your right. Keeping your hips and shoulders squared forward by bracing your core, press the cable forward until your right arm is straight. Perform all your reps on this side, then switch sides and repeat. (To make it harder, switch your stance so that your right foot is in front when you press with your right arm. To make it even harder, try to perform the presses with your feet even with each other, about hip-width apart.)

Beat Stress While You Train

All this stuff’s great, but even better: training your core while making a lot of noise and getting out tons of aggression. Your gym probably has a medicine ball and a wall—that’s plenty to do these rotary throws from Tumminello.

How to Do It: Stand about 3 feet to the left of a sturdy wall holding a medicine ball with both hands by your left hip. Keeping your hips facing forward, twist to the right and slam the ball against the wall. Catch it as it bounces off the wall, return to the start position, and quickly repeat. Perform all your reps on this side, then switch sides and repeat.