Take your ab workouts to the next level with this 5-move midriff workout by WH&F trainer Nichelle Laus.

One of the keys to a great physique is good posture and a toned midsection. Strong abdominal muscles will give you the necessary stamina you need to maintain proper form in your workouts and help you maintain the posture you desire in your daily activities.

This abdominal circuit, when coupled with nutritious food choices, will trim your waistline and define your midsection.

For a full-time four or six pack, perform the following five exercises twice a week for four weeks.

Gradually increase the number of repetitions you can complete only when you are able to do so with perfect form.

Photography: Dave Laus

Words/workout: Nichelle Laus, WH&F trainer // nichellelaus.com

Model: Tawny Clark

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1. Stability ball plank

Place your forearms in the middle of the stability ball with your feet on the floor, slightly wider than shoulder-width apart. Maintain a straight spine while you brace (tighten) your abdominals and glute muscles. Do not let your shoulder blades shrug or your midsection sag.

Hold the plank position for 30 to 90 seconds. Increase your hold by 10 seconds each workout until you can complete 90 seconds.