If you want a strong core, a regular Pilates practice should be on your workout plan. Not everyone enjoys the discipline of the practice, though, so skip the class and just steal one of the most effective moves, the Toe Tap, to add to other abdominal exercises for a quality workout.
Toe taps are accessible to most body types, even people with back pain, as it doesn't put extra pressure on your lumbar spine as crunches do. Use them as a warm-up for other more intense abdominal exercises or as part of a short, gentle self-directed Pilates sequence to strengthen your whole midsection.
How to Do Toe Taps
Toe Taps require no equipment, aside from a gym mat. You might choose one with extra cushioning if you have a sensitive tailbone.
Lie on your back with your arms alongside your hips. Lift your legs up and bend your knees so they are right over your hips and your shins are parallel to the floor.
Contract your belly to pull your navel to your spine. Slowly lower your right foot and leg to "tap" the floor. Keep the 90-degree bend in the knee as you lower. Return the right leg to the start and repeat with the left leg.
Alternate for 30 to 60 seconds. One set is sufficient.
Keep your head down for the entire duration of the exercise. If you feel pain in your back, lower your legs only as far as you can without aggravation -- you don't have to touch the floor to experience benefits.
Making the Exercise Harder
Toe taps become less of a gentle abdominal muscle warmup and more of a hardcore training move when you make some simple tweaks. The advanced progression involves tapping both feet to the floor at the same time as you keep your low back pressed to the mat. To really challenge your core, maintain the 90-degree angle at the knees
While the toe tap activates stabilizing muscles deep in your core, specifically the transverse abdominis, and your rectus abdominis, the superficial sheath of abs that shows up as a six-pack, it does not do much to train your obliques at the sides of your waist. The obliques are responsible for rotation and side-bending and should be addressed with other moves.
That doesn't make the toe tap exercise inferior to other ab exercises, because frankly no one ab exercise is comprehensive in training the core. It just needs some partner moves to offer the most to your core.
Additional Abdominal Exercises
Stick to gentle Pilates moves if you're just starting out. Follow the toe taps with a back stretch that involves hugging the knees into the chest. Then do knee rolls by lying on your back with your knees bent and your feet planted. Keep your back in the floor as you let your legs fall toward the right, then center, then left. Complete about 1 minute of this move using control.
Toe taps could also warm you up for other more intense moves, such as bicycle crunches -- also known as the Pilates Criss Cross -- mountain climbers, hanging leg raises and stability ball crunches.