Ask the Experts

Better your scoop, pick the right size ball and find out if you're ready for the next level

Q: What does my Pilates instructor mean when she tells me to "scoop" my abs?

Jillian Hessel responds: Joseph Pilates liked to call the abs the girdle of strength, because the abdominal muscles wrap around your torso. In order to understand how to scoop your abs, it helps to know where the abdominals attach in your body, and how they work.

Your body has four different layers of abs, similar to the layers of an onion. The outermost layer, just under your skin, is the rectus abdominis, which runs vertically from your pubic bones up to your sternum. This muscle helps your body flex forward.

The next two layers of abs are the external and internal obliques. These muscles help rotate your torso, and also tilt your pelvis forward or backward. They are key in helping to maintain a neutral spine position.

The deepest layer of abs is the transversus abdominis. Its primary function is to contract forcefully when you exhale deeply, such as when you cough or sneeze. When the transversus contracts, your lower belly should flatten as you pull the abs in and up. When you learn to work this muscle correctly, you will understand the Pilates scoop.

To practice scooping:

Sit up as tall as you can, lifting up out of your hips. Place your hands on your lower abdomen with your fingers spread apart. Imagine you have a belt slung low across your hips.

Inhale deeply through your nose for 5 counts. Exhale through your mouth for 5 counts, imagining you're tightening the belt and drawing your hipbones closer together. Your fingers should interlace as you exhale completely.

Jillian Hessel, author of Pilates Basics, teaches in Beverly Hills and internationally at lectures and workshops.

Q: What is the best way to choose the appropriate size of exercise ball?

Elisabeth Crawford responds: Manufacturers' guidelines suggest certain ball sizes based on height, but not everyone has success finding the right fit this way.

When a ball is first inflated, it feels quite firm. As time goes by, the material gradually stretches. Unless you add more air, the height and firmness decrease over time. A softer ball can provide a wider base of support and can be more comfortable when lying face-down on it. If this is the effect you are after, buy a larger ball and underinflate it. Exercising with a firmer ball requires more balance, due to the smaller area in contact with the floor. If you prefer the challenge of a fully inflated ball, try the size recommended for you: for people 5' to 5'6", use a 55cm ball; for 5'7" to 6'2", use a 65cm ball; over 6'2", use a 75 cm ball.

Your proportions can also come into play. For example, if you are 5'5", but have long legs and a short waist, you may be better off using the 65cm ball, rather than the recommended 55cm one.

Ultimately, the best way to determine the appropriate size is actually to sit on the ball. Your knees should be at a 90-degree angle or just slightly lower than the level of your hips. (If your knees are above your hips, it will be difficult to sit up straight.) If in doubt, choose a larger ball-you always have the option to underinflate it.

Elisabeth Crawford is a Pilates instructor at the San Francisco Tennis Club and author of Balance on the Ball.

>Q: How do I know when I am ready to progress to the next level of Pilates exercises?

Nora St. John responds: Pilates is an exercise system with well-defined skills required at each level, from beginner to advanced. If you are working with an instructor, she should be guiding you through the different levels. If you are working on your own or in a class, it can be a bit more difficult to decide when you are ready to move up a level. Here are some indications that you are ready for a more challenging routine:

1) Your workout feels too easy: Whether you are taking a class, working out on your own or working with an instructor, your Pilates workout should be just that, a workout. You should feel engaged, challenged and energized by the experience. Just remember, Pilates isn't only about working up a good sweat, it is also about correct form and paying attention to the details.

2) Your body has stopped responding: Oftentimes, when you first start Pilates, you feel all kinds of great changes during the first few months. Your muscle tone increases, your energy level goes up and you feel more comfortable in your body. If you keep doing the same workout in the same way, your body will eventually stop responding and you won't be as excited about what Pilates is doing for you.

3) You are bored, uninspired or unmotivated: In order to get the maximum benefit of Pilates, it is important to stay engaged in the process. Pilates is about using the mind and the body together, which means that the mind should not be planning tomorrow's outfit while the body is working out.

If any of these sound familiar, start to make small changes like varying the tempo to make moves more challenging, adding a prop, changing the order of the exercises or trying new moves. Working with a different instructor for a few sessions can also offer new challenges.

Nora St. John is director of Turning Point Studios in Walnut Creek, California, and Pilates on Tour.