Hatha simply refers to the practice of physical yoga postures, meaning your Ashtanga, vinyasa, Iyengar and Power Yoga classes are all Hatha Yoga. The word “hatha” can be translated two ways: as “willful” or “forceful,” or the yoga of activity, and as “sun” (ha) and “moon” (tha), the yoga of balance. Fitness Class Exercise is physical activity that is planned, structured, and repetitive for the purpose of conditioning the body. Exercise consists of cardiovascular conditioning, strength and resistance training, and flexibility.