10-Mile Walk Along the Hudson River after 2-Mile Walk Earlier that Day

Mowgli enjoying the sun; he was getting tired

The weather last Sunday was perfect for a long walk along the Hudson (from the 50s to Ground Zero; round trip: 10 miles).  I let myself be talked into it.  There were a lot of walkers, bicyclists, kids, and dogs.
  
We stopped very briefly several times to use the bathroom, chat with a friend/colleague we ran into, to give Mowgli some water, and to drop by a dog run.  At about mile 8, my left side started feeling off; foot, knee, hip, buttock.