Straight-Arm Side Plank on Balance Board
Begin by sitting on your right hip with your legs stacked to your left, your right arm straight, and your right hand on a balance board, placed directly underneath your right shoulder (not pictured). With legs and feet stacked, slowly lift your right hip away from the floor, keeping the right arm straight and extending both legs to balance in a side plank position (pictured).
Breathe steadily as you hold the side plank position for 15-30 seconds, keeping your abs engaged and the right side of your waist pulled away from the floor at all times. For added intensity, extend your left arm up toward the ceiling (pictured). Gradually work your way up to holding the plank for 1-3 minutes for an isometric core challenge. Repeat on opposite side.
Hold your body as still as possible and try to keep the balance board steady, too. Remember to breathe. Try to square your chest and shoulders with the front of the room, keeping your body in one plane. To decrease intensity, place left hand on the hip instead of extending it (not pictured).
Make it easier: Instead of stacking your legs and feet, stagger one leg in front of the other.
Muscles Worked: Abs, Obliques