Be a 'Mermaid' to your core

Personal trainer Brittney Atkin says exercises for the core are important because a strong core means being more flexible, having better balance and being less susceptible to injury.

She wants women to know that a strong core takes more than the typical abs routine based on crunches.

"Crunches work only the top of the rectus abdominus, or the two-pack," she says, "The core is the trunk of the body, the girdle. You need to engage the lower back, the lower abs and the obliques. Elderly and athletes alike need a strong core to prevent injury.

"You need your core to sit in a chair, to pick something up or to hold a kid. If you are holding a kid without a strong low back, you could get a lot of lower back pain. You need to have a tight midsection where all those organs are."

Atkin said any type of exercise that requires balance works the core. She suggests adding core work to your regular routine by doing traditional exercises on an unstable surface--like standing on a rolled-up yoga mat while doing bicep curls.

Atkin warns, though, that core exercises won't shrink the midsection. She said a smaller waist comes from good nutrition, but core work will firm muscles.

"Trainers have differing opinions, but I personally think the core rejuvenates so quickly compared to other muscles like the biceps or triceps that you can work it every day. If you are super sore, then take some time off and recover," she said.

Atkin suggests the following exercise be a part of a woman's core work:

Mermaids: Rest your right hipbone on an exercise ball with your feet against a wall, right foot in front of the left foot. With hands by the ears, crunch up toward the hip 12 times and switch to the left side. Complete three sets for each side.

Muscles worked: Obliques (love handles)