Like the framework of a mighty skyscraper, the core helps humans hold up the weight of the sky. Stay firm against the firmament with today's Groupon to CoreVibes Studio's location at the Cloverdale School. Choose from the following options:

• For $15, you get two Pilates mat classes (a $15 value/class; $30 total value). Classes are held Mondays at 4:30 p.m.
• For $15, you get two Gentle Pilates classes (a $15 value/class; $30 total value). Classes are held Tuesdays at 12:15 p.m.
• For $15, you get two Vinyasa (flow yoga) classes (a $15 value/class; $30 total value). Classes are held Mondays at 5:30 p.m.

CoreVibes Studio's certified instructors teach one-hour classes that strengthen cores, stretch limbs, and unwind minds of all ages and skill levels. Vinyasa, a full mind and body workout also known as flow yoga, fuses breathing with movement using large-scale adhesives. Instructor Paula Chang runs yoga poses together, creating a coordinated dance that exudes grace, strength, and freedom.

During Pilates classes, which help strengthen cores, Lynne Ellen Kershaw steers students through excercises that improve strength, flexibility, and postural habits. Pamela Kennedy's Gentle Pilates, customized for new students, mature students, or those suffering from back problems, modifies its tempo so students may learn its movements more slowly and build their confidence with the routines. Students must bring a mat to class, and they are asked to wear comfortable clothing that bends to the body's contours like a sopping-wet shadow.