FIVE-MINUTE STANDING AB WORKOUT

If you're like pretty much everyone else in the world, you probably feel incredibly accomplished when you get through a quarter of your "must-do" list on any given day. It's no wonder workouts -- especially ab workouts -- get dropped to the bottom of the list. Which basically means they don't get done at all.

The thing about abs, though, is that a little bit of work really can go a long way. You're already engaging your core during practically everything you do, so adding a few minutes of ab work here and there can pay off big time when it comes to achieving that rock-solid midsection. That's assuming, of course, you're watching what you eat and exercising regularly -- there are no miracles here, people.

If you're looking for a way to squeeze in your ab work, check out these short and straightforward routines.

STANDING AB WORKOUT

Squeeze this five-minute circuit in while cooking dinner or while keeping yourself occupied during a ridiculously boring conference call -- just remember to mute your mic. Perform each exercise for 30 seconds, cycling through the circuit twice.

Twisting march

Stand tall with your feet hip-distance apart, placing your hands behind your head, elbows pointing outward. Tighten your core and lift your left foot from the ground, bending your knee to draw it as high as you can in front of your body. As you lift your knee, twist your torso to the left, trying to touch your left knee with your right elbow as if performing a bicycle crunch. Place your left foot back on the floor as you twist your torso back to center before repeating on the other side.

The rainbow

Stand tall with your feet shoulder-width apart. Place your hands behind your head, elbows pointing outward. Tighten your core, and keep your hips steady as you bend to the right, leaning as far to the side as you can. At your lowest point, further contract your obliques to reverse the movement and lift your torso back to standing. Repeat to the left side so the full side-to-side motion looks like you're drawing a rainbow with your head and elbows.

Extend and crunch, right side

Stand tall, feet hip-width apart. Extend your arms over your head and shift your weight to your left foot. Point your right foot behind you with your toes on the ground.

Tighten your core and tip forward from the hip, tilting your torso toward the floor to an angle between 30 and 45 degrees. From this position, draw your right knee up and forward forcefully as you simultaneously pull your elbows straight down to your sides, crunching your abs as you do so -- imagine you're pulling someone toward you so you can knee them in the gut.

With control, extend your arms and right leg to return to the starting position. Continue as fast as you can, focusing on engaging your abs.

Extend and crunch, left side

Perform the same exercise you just performed, this time on the opposite side.

Windmill

Stand tall with your feet wider than shoulder-width apart, your arms extended laterally from your shoulders, as if you were a star. Engage your core and tip forward from the hip, rotating your torso to the left as you reach your right arm across your body to touch your left foot. As you perform the movement, look over your left shoulder and try to keep your torso straight and your hips steady by engaging your abs, obliques, and low back.

Reverse the movement and return to the starting position, engaging your glutes and hamstrings to help pull you to standing. Repeat to the opposite side.

Five-minute office chair ab sculptor

Surely you have a few minutes during your day to eke in a quick ab routine at work. All you need is a rolling office chair and a wall to stabilize said rolling chair. Perform each exercise for 30 seconds and cycle through the circuit two times. Consider this the healthy person's smoke break.

Chair plank

This exercise can be performed with your chair pushed against a wall for extra stability, or free-standing for a greater challenge.

Place your hands on the center of your chair's seat, pressing straight down through your palms. Make sure you're not pressing forward, which would cause the chair to roll. With your shoulders directly over your palms, step your legs backward, planting the balls of your feet on the ground so your body forms a straight line from head to heels. Hold the position for the duration of the exercise.

You can make the move harder by engaging the swivel on your chair and rotating your palms to the right and the left as you hold the plank.

Reverse crunch

This exercise actively uses the rollers on the chair, so make sure you have some room to move.

Start on your hands and knees in front of your chair, but facing away from your chair. One at a time, lift each leg from the floor, placing the top of each foot onto the chair's seat. Extend your legs so you're in a high-plank position, your body forming a straight line from heels to head.

Now engage your abs and press down through the tops of your feet as you bend your knees, drawing them toward your chest. The rollers on the chair will cause the chair to roll toward your body. Once you've pulled your knees as close to your chest as you can, reverse the movement, extending your legs as you roll the chair away.
 

Chair side plank, left side

This exercise can be performed with your chair pushed against a wall for extra stability, or free-standing for a greater challenge.

Kneel next to your office chair so your left side is against the chair. Lean to your left, planting your left forearm in the center of the chair's seat, your forearm placed perpendicularly to your body. Press straight down through your elbow as you lift your right hip, carefully extending your legs, stacking them one on top of the other. It's important to center your shoulder directly over your elbow to keep the chair from rolling. Hold this position, your body forming a straight line from heels to head, for the duration of the exercise.

Chair side plank, right side

Repeat the same side-plank exercise to the opposite side.

V-sit extension

Perch on your tailbone toward the front of your chair's seat. Lean back, your torso straight, and grasp your chair's arm rests or the edges of your chair, just behind your hips. Lift your knees up so your thighs and torso form a "V." From this position engage your abs and extend your legs as a single unit, controlling them so your feet don't drop to the floor. After extending your legs fully, draw them back toward your body to return to the "V" position.