Kumbhakasana also known as the plank asana is the most simple yet effective pose in yoga. It strengthens and tones your arms shoulders back buttocks thighs and not to mention your abs. With all the focus on your core this asana is great for runners and is the best aasana to get rock hard abs. Steps to do this pose: Lie flat on your tummy on the floor or your yoga mat. Place your palms next to your face and bend your feet so that the toes are pushing off the ground. Push off your hands and raise your buttock into the air.