We see photos of Demi Moore and Jennifer Aniston in bikinis and wonder: Can I look that great in a bikini after 40? Absolutely.

After 40, it may not be about having washboard abs. Working out abdominal muscles is to strengthen your core — something that become s more important as we age. In fact, the most important moves to do as we age are for strengthening the core. I call the midsection the body’s “command center,” because it protects and supports the rest of your body.

If your core is unhealthy, it will compromise the health of your entire system. It’s the place where all movement is initiated, and the source of our bodies’ deepest powers. It’s also the factor that determined whether we move freely and with ease, or whether we’re weighted down by aches and pains.

A strong core is so important that it actually affects your skin. Even if your skin — after pregnancy and a handful of decades  — has lost collagen, becoming looser and thinner, exercise can help. Ab exercises tighten the muscle under the skin and give it a tighter look.

But, you can do a million crunches and they won’t get you the sexy look you desire. Why? Because you must work out all three sets of the abdominal muscles: the rectus abdominis, which runs from the rib cage to the tips; the obliques, which pull in the waistline; and the transverse abdominis, the core muscle that spans the midsection.

The rectus abdominis can be toned with crunches, or any moved the brings the shoulders close to the hips. Working out the obliques with rotating movements such as bicycle crunches or side planks helps trim sides. When you suck in your stomach, you’re engaging your transverse abdominis.

Try these two exercises to blast abs fast and train all three of your belly’s muscle groups:

Charlie’s Angels:

1. To work the obliques, sit upright with knees bent, feet on the floor, chest lifted.
2. Lift your feet off the floor, tucking your knees into your chest.
3. Interlace your fingers and point them forward.
4. Swivel your knees side to side. Lift your chest and spine straight, making sure not to slump.

If this move is too challenging, place your hands on the floor or start by balancing with your feet off the floor before adding the swivel.

Forearm Plank With Swivel

1. Start in a plank position, resting on your elbows. Keep the shoulders back and down, and the next nice and long throughout the movement. Beginners may rest on the knees instead of a full plank.
2. Keeping your abs engaged, slowly swivel the hips underneath you to the right. Feel your obliques driving this motion as you swivel to the other side with a slow, controlled motion