Watch free exercise videos with ab exercises from the Get a Flat Belly in 6 Weeks ab workout plan at FitnessMagazine.com.
Front plank: Start on all fours. Now, keeping your back straight and your abs pulled in tight, drop down to your forearms and extend your legs behind you into a plank position. Hold for 30 to 60 seconds. You should be resting on the balls of your feet and your forearms, keeping your back straight,