“> This challenge is all about balance exercises. The task is to walk from one end of a narrow surface to the other without looking down, walk backward to the starting point, then finally walk to the middle of your imaginary “balance beam,” squat down as low as you can, and rise back up to standing. After you’ve mastered this, do it all again with your eyes closed. Muscles worked: Balance work strengthens your hip stabilizer muscles, including your glutes…