Parcours Trail - Sand Run Park - Summit County MetroParks
The Summit County MetroParks page rates their trails on a difficulty scale of 1 - 3. They call this one a 3, and it deserves it. Its fairly short (1.2 miles) but the terrain is pretty steep.
if you want an additional challenge on top of the hike, there are varoius point along the trail where they provide equipment for doing various cardiovascular exercises:
This trail has some great scenery, provides a nice challenge, and keeps you far enough away from the road that you really feel like you're surrounded by nature. Excellent trail. I'll definitely be back here again.