core exercises

When it comes to strengthening your middle, planks pull your entire core together. They can be your best friend or your worst enemy: it's a love-hate relationship. To switch up your basic plank incorporate a twisting motion. This variation gives you the same results while also engaging the sides of your core. Hello, obliques!

Start in a Plank

• Begin in a plank position.
• Make sure your hands are directly under your shoulders and your legs are squeezed together. Create one long line from your heels all the way to the crown of your head.
• Hold this basic plank for 10 to 20 seconds to warm up your core before twisting. Make sure your back stays lifted with open shoulder blades to prevent your chest from sinking down.

Lift Your Knees

• Hold your plank position and bend your knees, allowing them to slightly hover over the ground.
• Straighten your lower back by pulling your abs in, in preparation to start the twist.

Twist It

• In one fluid motion, twist your knees to the right, initiating the movement from your obliques.

• Return to the center, then twist to the left. Do this 10 times on each side.
• For more of a challenge: end the exercise in a traditional plank with your knees extended and hold it for 10 to 20 seconds.

Learn a slightly easier variation after the break.

While you can work your abs lying down, the most effective core exercises are functional moves done standing. Functional exercises mimic everyday moves and easily translate to real-life activities. Equinox trainer Lauren Fairbanks recommends the wood chop using the cable pulley machine to strengthen the abs and back while sculpting a toned torso. "It's a full-body move that works the glutes and the shoulders, and just about everything in between." The primary focus of the exercise is the abs, especially the obliques, which drive the twisting motion.

Starting Position

• Attach the double rope handle onto the cable. Set the weight to 15 pounds.
• Stand your right side toward the machine about two feet from the machine. Grab the handle and open feet to a stable and wide stance.

The Exercise

• Exhale, pull abs to spine, and rotate torso to pull cable down to the outside of your left knee while simultaneously bending it. Imagine you're swinging an axe across your body.
• Keep your arms straight and do not round your back.
• Reverse the motion, controlling the weight on the cable as you return to the starting position. This completes one rep.
• Do 12 reps on each side for three sets.

Source: Megan Wolfe Photography at J+K Fitness Studio

If you're looking to amp up your fitness routine, you need to get unstable. Performing classic single-leg exercises while standing on a foam pad, like the one pictured above by Aeromat, is simple way to do this. The squishy surface forces your core and legs to work harder, increasing your strength gains and caloric burn. Standing on the soft surface also strengthens your feet and ankles, which is important if you're flirting with the barefoot running trend or plan to spend lots of time hiking hilly terrain this Summer.

To get started, try this three-exercise progression I learned from my Equinox trainer Lauren. Once you've mastered a variation, try the next level up. As you experiment with these moves, you will feel your weight shift from side to side on your foot, which means the muscles that support your arch and ankle are working. If you find your feet cramping, spread your toes wide in your shoes or try the exercise in just socks.

Learn the moves after the break.

You've heard it before: work on your core muscles so you can have everything from better balance to better cardio performance. But what if there was no benefit to having strong abs besides a celeb-worthy midsection?

Three studies reported in The New York Times show that you may or may not be getting what you want out of your ab exercises. One study looked at a group of college rowers and found that those who did eight weeks of core prep before a rowing test didn't do any better than those who didn't. Another study looked at healthy volunteers and found there was no correlation between a sturdy core and their ability to perform in a bunch of tests that included sprinting, jumping, and balance tests.

Read on for more after the break.