What is TRUE Abdominal strength and what does that mean? Yamuna Body Rolling has routines that focus on improving both strength and flexibility with detailed attention to the core. Yamuna principles demonstrate why the classic “Crunch” makes no sense when training the center of your body. Developing length and tone in the center of your body increases range of motion in the torso, reduces lower back problems, improves posture, lifts the upper body, and improves organ function. A great deal of focus is placed on breathing while working deep into the center.