Single-leg dynamic stability is important, as is core stability. This exercise challenges both and is great for almost any sport. Add it to your routine as a warm-up or routine. I am using a 10 pound medicine ball, but it’s best to start light and stay light as the focus of this drill is quality of movement; not strength. Balance is something I work on quite a bit to keep my feet intrinsic muscles and hips strong for the pounding of running. Keep your routine fun and add these rainbow passes to your gym routine. Enjoy!