Core Training And Balance by Gary Gardiner | Jul 7, 2019 Core Training And Balance – A personal trainer works his way across the rock-fill at the base of Hoover Dam using a medicine ball to shift his center of gravity as he works for core strength and for balance. My Final Photo for July 7, 2019. Submit a Comment Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website This site uses Akismet to reduce spam. Learn how your comment data is processed.