Can’t cram enough gym time into your calendar? This move from trainer Nick Tumminello lets you activate those deep core muscles without leaving your desk. Do it anytime you need a break at work. For best results, use a stable (read: not swivel) chair.

Upright Bird Dog

Sit on the edge of your chair with your feet flat on the floor, resting your hands on the seat next to your hips (A). Keep your hips, knees and ankles bent 90 degrees. Shift your weight forward off the seat so that all your weight rests on your hands and feet.

Bracing your abs and keeping your torso stable, lift your left foot off the floor and your right arm straight in front of you (B).

Hold for 10 seconds, then repeat the move with the opposite arm and leg. That’s one rep; do three to 10 reps.

Do this simple move three times a week and you’ll be one step closer to a sexy core.