Difficulty level: 1
Cross your ankles and lift your knees. Cross your arms at your chest and lift your shoulders off the floor. Do 3-5 sets, 10-15 reps in each.
Difficulty level: 2
Lying on your back, put your arms straight against the floor. Do “lifts” holding the top position for a few seconds. Be careful if you have problems with your back. Again, do 3-5 sets, 10-15 reps in each.