Russian twists –
Lie down on the floor in a sit up position (your legs should be bent at the knees). With a weight or without, twist your abdomen and touch both of your hands on the floor to the left of your hips and then turn and touch both your hands on the floor to the right of your hips. Repeat.
Lie down with your hands over your head. Simultaneously raise straight legs and torso, reaching towards your raised feet (your body should look like a “v”). Return to starting position. Repeat.
Get into pushup position on the floor. Now bend your elbows 90 degrees and rest your weight on your forearms. Your elbows should be directly beneath your shoulders. Hold the position for as long as you can- start with 30 seconds and work your way up to 3 minutes!
Stand with your feet slightly wider than your hips (your toes should be pointed slightly outward). Look straight ahead and pick a spot on the wall in front of you, use this spot as an anchor, looking at it the entire time that you squat. Slowly sit back as if you’re holding groceries and can only close the door to your car with your butt. Make sure your knees do not lean over your toes. Keep your abs tight! Add a barbell or kettlebell for a bigger challenge and better results. Repeat.
Begin in a squat position with your hands on the floor in front of you. Kick your feet back to a pushup position. Return your feet to the squat position. Jump up as high as possible from the squat position and jump back into the squat position. Repeat.
Mountain Climbers –
Get into a pushup position, making sure your shoulders are straight above your wrists. Bend your right leg up towards your chest, return the right left, then do the same with the left. While holding upper body in place, alternate legs as quickly as possible. One leg should be extended while the other is bent towards your chest at all times. Repeat.