Hasta uttanasana or raised arm pose is a great pose to stretch and tone the muscles of abdomen and arms. It helps to remove unwanted belly fat and achieve a flat stomach. Learn and practice Hasta Uttanasana @ https://www.youtube.com/watch?v=kQuRvneuIYg You may also refer https://www.youtube.com/watch?v=OkeXtEV_0ks for developing a complete plan for flat abs.