Get in the plank position. Keep your core tight. Raise your right arm and left leg so they are parallel to the ground. This is one rep. Alternate sides.
Knee Raises
Using your dip station (or something else, like a countertop) for support, use your lower abs to raise your knees as high as possible. This is one rep.
Bicycle Crunch
Lie on your back, knees bent at a 90 degree angle, hands behind your head. Bring your right elbow to your left knee. This is one rep. Alternate sides.
Tabata: Up & Down Plank
Start in the plank position on your elbows. Raise your body up into a push up position. Lower yourself back down to your elbows. Keep your core tight and your back straight throughout the movement. This is one rep.
Alternating Dumbbell Row
Stand with your knees slightly bent and keep your back flat. Hold a dumbbell in each hand (5-10 lbs.) and alternate drawing your elbows to the ceiling.
Rear Lateral Raise
Stand with your knees bent and keep your back flat. Hold light weights in your hands. Raise both arms out to the side so that your arms are parallel to the floor. Lower back down to starting position.
Pullover with Dumbbells
Light on your back with your knees bent and feet flat on the floor. You can use a bench or a stability ball for an added challenge. Hold a 5-10 lb. weight with both hands above your head. Resist the movement as you lower your weight behind your head to the floor. Bring your hands back to starting position.
Tabata: High Knees
Stand tall. Draw your knees, one at a time, to the ceiling as high and as fast as you can. Use your lower abs to draw your knees up.
V-Sit with a Twist
Sit on the floor with your legs bent at a 45 degree angle, heels lightly touching the floor, and lean your upper torso back, contracting your abs. Hold a weight for added resistance. Twist your body from side to side, keeping your core tight.
Plank with Leg Raises
Start in a straight-armed plank position. Keep your core tight and your back flat. Alternate raising your legs up to the ceiling as high as you can while maintaining proper form. Each leg lift is one rep.
Windmill Crunch
Lie on your back, arms to the side and your legs straight up in the air. Resist as you lower your legs to one side, raise back up to center and lower to the other side. Each time you lower your legs, it counts as one rep.
Tabata: Mountain Climbers
Get into a plank position. Keep your core tight and your back flat. Alternate drawing your knees into your chest as fast as you can while maintaining proper form.