In TODAY.com's Expert Tip of the Day, a trainer reveals her favorite exercise for a more defined waistline and strong core ...

The stomach vacuum exercise involves breathing out air while sucking in the stomach to engage the core. It is an isometric exercise to strengthen the core muscles. The abdominal muscles, part of the ...

The stomach vacuum exercise contracts your deepest abdominal muscle. You can do this exercise in multiple positions, including lying down or standing. Despite its name, a stomach vacuum isn’t a ...

Your abdominal muscles surround your trunk between the rib cage and pelvis and keep your abdominal organs safe. Your core abdominal muscles also support your trunk and allow movements while keeping ...

Tone your core and slim your waist with these 7 simple, effective at-home exercises designed for women. No gym required—just consistency and dedication. From standing twists to leg raises, these moves ...