This is another post in our series of Fitness Saturday exercises and workouts appropriate to women in the second half of life. Personal trainer, group fitness instructor, and professional athlete Cassidy Watton, based in Malibu, California, is our fitness guru.

A strong core is the key to a happy, healthy, and whole life. The “core” consists of the transversus abdominis, rectus abdominis, and the internal and external obliques. From betterhealth.vic.gov.au:

“Think of your core as a strong column that links the upper body and lower body together. Having a solid core creates a foundation for all activities. All our movements are powered by the torso – the abdominals and back work together to support the spine when we sit, stand, bend over, pick things up, exercise and more.”

As you can see, the responsibilities of the core are many; a weak core can set off a chain reaction of problems and pain. 

We have all had our fair share of “15 Minute Core Blast” videos, plus those “5 Minutes to Flat Abs” magazine articles that we laminated, pinned to the wall, and vowed to follow every day. The core exercise I would like to share is not fancy or flashy; it just works. It is not just for show, it’s also for function. 

Today’s exercise is the “Hollow Rock,” an isometric abdominal hold that can be done any time, anywhere and can always be improved upon. Isometric exercises are exercises done in a static position, as opposed to a dynamic one where you move, like the sit-up. 

To perform a Hollow Rock, begin by lying flat on your back. First, squeeze your glutes, then raise your legs and shoulder blades off the ground, toes pointed and about 4 inches off of the ground. The lower back remains flush to the ground. Think about bringing the rib cage and pelvis closer together.

In the first version of the Hollow Rock, the arms remain by your side, palms facing up.

In the more advanced version, the arms come overhead, with your biceps by your ears. Simply hold this position for as long as you can without compromising form.  As soon as the lower back begins to arch, or your glutes are no longer engaged, or you are shaking, stop. It is okay if sets are as short at 10 seconds to begin; they will get longer with practice. Do 3 to 5 sets or try to accumulate 2 to 3 minutes held in this position in as many sets as it takes.

In the third and most advanced version, rock back and forth, holding perfectly tight form. The curve of your body should look like the curve on the bottom leg of a rocking chair. 

This exercise will hit every area of the core while teaching your body how integral it is in getting your body to work together as a unit. Give it your first try now, and see how you improve in one month with just a few minutes of Hollow Rock per day.

Happy Rocking!