A personal trainer outlines his best seven-day core strength challenge for a flatter stomach and tighter midsection.

Strength training is important for everyone. We all need this type of movement to build and maintain muscle and to stay healthy and mobile as we age. Stephanie Mansour, a personal trainer, weight-loss ...

Some people work on their core because they’re hoping for a 6-pack or a flat tummy. But having a sturdy core provides you with much more than a toned look. A strong core — which includes the back, ...