The total LA experience and a good workout at your own pace can be found at Runyon. We've gone so much that we named our cat Runyon. There are 3 distinct trails if you come in from the Fuller/Hollywood side. The left one is the most challenging mostly because I'm wondering how people do that wearing flip flops!? ;-)
Great trail for a quick hike. Start on Fuller Ave. There are three options. Go to the left and once you pass through the gate take a sharp left and go up 2 peaks. This is challenging as the hills are steep. You can continue up more towards the gates on Mohalland or loop back down the pavement. Takes about 1 -1.5 hours depending on which route you take. Option 2 instead of hooking the sharp left continue up pavement and loop around and down the hill to the right. Option 3 at the beginning of the Fuller Ave entrance keep straight instead of going to the left. This will loop you to an observation area. When you see the opening take a sharp left as the trail narrows. Climb up the steps and enjoy the views and the leg burn! Once you get to the top keep walking until you hit the pavement. Continue to the left to head straight down (avg 45 mins) or if you feel like extending go to the right and wander up the pavement until you see a dirt path on the left and take it for higher elevations which tacks on another 30 minutes to your hike. Option 1 is difficult. Option 2 is easy to moderate. Option 3 is moderate. Great city hike to build endurance and check out great views of the city, The Griffith Observatory, The Hollywood Sign and the snow capped mountains!