Some of the best beach running in Florida can be found in the stretch from Panama City Beach west to Destin. The names of the beaches change along the way, but this is 40+ miles of wide, continuous beach. The sand, especially near the water, is reliably compact for running. And with the exception of Panama City Beach proper, the area is generally free of high-rises. A few highlights:
Panama City Beach Area. Popular, signature beach. A nice stretch is ~5 miles east to St. Andrews State Park, where there some additional trails for running and a 2-mile paved park road that makes for a decent running loop. Or, head west for up to 15 miles to St. Helen State Park. Be sure to include a jaunt out the fishing pier, ~1 mile out and back!
There’s a break at St. Helen State Park, which depending on season/tides can be crossed by foot.
West of St. Helen State Park. Nearly 30 miles of continuous beach running is possible west to Destin. It’s ~10 miles to Grayton Beach State Park, starting at Rosemary Beach and passing Ayls Beach and Seacrest Beach, among others. From Grayton Beach continuing west: ~2 miles to Blue Mountain Beach, 10 miles from there to Miramar Beach, another 6 miles to Henderson Beach, and another 3 miles to the Destin East Jetty.