It may be too late to get in shape for the full 15k Gate River Run through downtown Jacksonville Saturday, March 10. But you can participate in the free one-mile Brooks Rehabilitation Challenge Mile run and your kids can lace up for the Adidas Junior River Run, also one mile. The Brooks run starts at 10:15 a.m. and the Junior run starts at 11 a.m., both beginning on Duval Street and ending inside the Jacksonville Fairgrounds. After, the post-race celebration goes on at the Fairgrounds with live entertainment and vendors.