Push-ups are one of the best exercises for toning your upper body and core. So if you are used to doing push-ups with your hands wide out here is a push-up variation you can try for a more defined and toned arms. You will just need an exercise ball or a Swiss ball to strengthen to further challenge your core arms and shoulders. The exercise will also help increase your flexibility in posterior muscle groups throughout the body. In this exercise the shoulder girdle expands and stretches various muscles around the shoulders. While you exercise on the unstable platform of