6. Ballerina twist
This exercise is super easy to do even if it looks and sounds difficult, all you have to do is to sit with your legs extended, toes pointed, and thighs together, then lean backward and put your left forearm on the mat. Once done, raise your right arm over your head and twist left. This is basically it, make sure to return to the initial position and do the same thing with the other and make sure to keep your abs engaged.
7. Twist
First, sit on a mat and lean backward to engage your abs, then put your feet flat on the mat in front of your bent knees. Star twisting slowly from side to side using a weighted ball and make sure to keep your abs engaged the entire time.
8. Mountain climbers
Put both of your hands on the ground and get into a plank position with your feet behind you balanced on their balls. Once done, pull up one knee towards your chest and get it back to the initial position, then do the same thing with the other knee Start slowly, then build up speed gradually.
9. Barbell rollout
Load a bar with a 10-pound weight on every side to make a makeshift ab-wheel. Sit on your knees, lean forward and grab the bar shoulder-width apart, then push the weighted bar away from you slowly until your hips start feeling tired, then slide it back toward you. You can increase the added weight over time.
10. Pike to Superman
Start by getting into the pushup position, then slide a stability ball under your shins/ankles and adjust it until your toes stand on it. Now, bend your hips and start rolling the ball forward until your body becomes vertical to the ground, then roll the ball backward and repeat the exercise.