Just west of the Vilamoura Marina, a series of enjoyable and scenic trails ride along the red cliffs above the beaches. There are great views of the cliffs and the sea below. A good place to start is the parking lot off and enjoy the series of meandering dirt trails. You can stick close to the edge (plenty wide, decent footing), for ~4 km west to Rua de Falésia. There are also trails that wander inland. At the east end, the inland trails approach the golf course, while further west, there are parks, recreational trails, and an observatory. The surface is dirt, and can get muddy in rain.
There are some spots along the way with ramps or stairs going down to the gorgeous beach. The sand is a bit fine for running, but can be OK close to the water near low tide.
Add-On: This can be done in combination with all or part of our tour of Vilamoura’s marina, beach, and seafront promenade. Route here.