Great loop hike only about 90 minutes from DC.
Relatively few stream crossings, all pretty easy. If the water level is low you won't even get your feet wet.
Uphill climb getting to Signal Knob is a good workout to get started. Once you pass the TV radio towers on your right, just ahead are a few rocks great for perching on to stop for lunch. Good views into West Virginia when the weather is clear.
I like this route counterclockwise. After you hit Signal Knob you walk along a fire road for about two miles. It's steep but downhill goes pretty fast. Going up would be both boring and hard.
Overall well-marked trail, good views, good workout.