While improved strength and muscle tone are reason enough to add planks to your workout routine, this move has many other health benefits that often go overlooked.

Planks have exploded as one of the greatest core workout moves, and for good reason—they’re killer for your abs while also working the rest of your body. If you’re getting a start on your summer swimsuit bod, planks might be your best friend. While improved strength and muscle tone are reason enough to add planks to your workout routine, this move has many other health benefits that often go overlooked. Here are 4 things you should know about planks.

1. They improve your posture
Who knew that planks help to improve your posture? (Your mother will be so proud!) Planks work your back, chest, shoulders, and neck in addition to your abs. Strengthening these muscles allows you to keep your shoulders back and your chest high. Planks also develop isometric strength in your core, which helps you stand up straight or sit up straight for long periods of time.
Try a plank with elbow to knee rotation: Get into a basic plank on your hands, then drive your right knee and your left elbow to meet in the middle of your body. Return to the starting position, and repeat on the other side.

2. They’re easy to modify
Planks don't discriminate. Whether you’re a beginner or a fitness guru, planks are a great workout move because they're easy to adapt to your specific level. As a beginner you can start with basic plank moves and hold them for shorter amounts of time. For example, hold a basic elbow plank for 15 seconds. As you become more advanced, increase your time and try a harder position like a plank with leg extension (below). Before you know it, you’ll be holding a plank with leg and arm extension for a minute plus!
Try a plank with leg extension: Get into a basic plank, and then lift your right leg a few inches into the air so that your toes are off of the ground. Hold this position for a count of 10, and then switch to your left leg. As you improve, try extending your opposite arm in addition to your leg. Really advanced? Extend your same side arm and leg.

3. They increase your flexibility
Planks are a great way to stretch out the back of your body, particularly your legs. Pressing your thighs up into position stretches your hamstrings while also stretching the arches of your feet. Side planks stretch out our sides, as well, especially when you extend your arm up over your head in line with your body. Planks provide the best of both worlds—stretching and strength training in one!
Try a rocking plank: Get into a basic plank and use your toes to rock your body forward and backward a few inches either way. This will help you to sink into the stretch in the backside of your body.
4. They test your balance
One of the reasons that planks and side planks are such great core exercises is that they require you to engage your abs to the max in order to stay upright. Particularly during side planks or planks with extensions, your balance is tested and therefore, improved. If you really want to work on your balance, planks on a stability ball are a good challenge, as well.
Try a side plank with leg raise: Get into a side plank with your legs stacked. Lift your top leg up and hold for a count of one. Lower it and repeat. Switch sides after working your first side.

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Jennifer Cohen is a leading fitness authority, TV personality, best-selling author, and entrepreneur. With her signature, straight-talking approach to wellness, Jennifer was the featured trainer on The CW’s Shedding for the Wedding, mentoring the contestants’ to lose hundreds of pounds before their big day, and she appears regularly on NBC’s Today Show, Extra, The Doctors and Good Morning America. Connect with Jennifer on Facebook, Twitter, G+ and on Pinterest.