Equipment: A mat, a stability ball and a three- to five-pound dumbbell.
Warm-up: March in place or walk briskly for about three minutes.
Repetitions: Begin with two sets of each exercise, working up to three sets as your abs get stronger. Perform each for the suggested reps or time (or less if you can’t hold good form). You should be able to do two sets of three moves in about six minutes (about eight to 10 minutes including warm-up).