5 Ways to Get a Flat Stomach Standing Up

"This is a fantastic seat exercise that relies less on upper-body strength and places a deeper focus on your core," says Becker.
1. Place one forearm over the other on your piece of furniture and lean forward so that your head rests on them. Walk your feet back so that they’re directly under your hips.
2. Soften both knees and then draw your right heel up toward your seat, pointing your toes.
3. Lift and lower your right leg about two to three inches.
Reps: 45 seconds to one minute on each leg Bonus: Extend your leg to sculpt your hamstring and create an extra challenge for your core.