The plank is one of the best exercises for stabilizing your core, which improves balance and posture. There are lots of plank variations, but you should do your best to master the basic plank before leveling up - try to build up to a one minute hold. When done properly, one minute can be quite challenging!
Common plank mistakes include:
the booty is too low, creating a sagging
the booty too high, taking the challenge off the core
the neck is not in alignment
the elbows are hyperextended
sinking into the wrists
It helps to ask a friend to spot you, but if you don't have a workout buddy nearby here are some things you can do to check yourself:
make sure your gaze is 10-12 inches in front of your finger tips
ensure that your ears, shoulders, hips and ankles are in a straight line like a board
face the "eyes of the elbows" toward each other
push away from the ground through your palms and finger tips Don't sacrifice form for duration. When you feel like your form is starting to slip, just take a break and get back in, as soon as you're able!