When it comes to improving core stability, the plank has your back (and your front!). By working your transverse abdominis — the deep core muscles that wrap around your middle — as well as your back, shoulders and glutes (yes, you should activate your butt, too), you get a full body burn in one isometric movement. But the best thing about planks: You can continuously switch them up and make your muscles work even more. Check out these creative twists on a typical plank routine and you’ll see what we mean.
I’d stand outside restaurants pretending to stare at my phone while my family and friends munched on dessert. There would be days when I would be completely broken from the inside-out after training with weights in the morning and running a 2k in the evening on no fuel. I’d find excuses to stay at home on the weekends and give up meeting friends only to stay away from food and drinks which didn’t align with my goal. I got used to awkward situations while placing ‘weird’ food orders at restaurants and stares from coworkers while shaking up my protein mix.
Try starting your day off eating heavier, and ending on a light dinner. Instead of waking up and running out of the door with a banana, eating a small lunch, and then eating a hefty dinner, try making your breakfast your heaviest meal and your dinner the lightest. For carb intake at dinner time, try to ingest the wet types of carbs that are in high-water, medium-fiber foods.
On hardwood or tiled floor, place feet on two sliders and assume a high plank position (hands under shoulders, soft bend in elbows, butt and core engaged). Pull feet in toward chest, bending knees until you’re in a bear plank, knees below hips, but still lifted off floor. Slowly push feet back to high plank. Continue to repeat. To make it easier, move one leg at a time.
But instead of just trying to perform as many reps as possible, slow down and really focus on the quality of the movement—especially the eccentric, or downward motion, of the exercise, he says. “The eccentric contraction is the most important phase when sculpting any muscle.” Plus, focusing on quality over quantity will help protect your back (some experts say crunches can be potentially troublesome for guys with back issues.) 
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