Training for Whitney you need some gain. I live in SCV and work in Simi, here are a couple great hikes.
1: The Beast: 9.8 mi RT with 2400' elevation gain. Take the 14 North into SCV and exit at Newhall Ave, turn right and park in the park and ride. Looking to the east you'll see a hill with a fire road heading up. Take the fire road all the way to the Radio Antennae (Los Pinetos Station #1) you see from the base. There are a few forks int he road, but the general rule is "keep going up". Once you top out the divide you can get some pretty cool views of SFV. On one occasion I could see all the way out to the sea past Santa Monica.
2: Rocky Peak via Hummingbird Trail: 8.6 miles RT and 2100' of elev gain. You take the 118 over Santa Susana Pass into Simi Valley and take the first exit onto Kuehner. Just north of the freeway park in one of several pullouts alongside the road. Cut east across the path leading across the dirt lot until the trail becomes more distinct after crossing a dry creekbed. Hang a left once the trail dead ends onto Rocky Peak Road (2.7 miles in). Follow Rocky Peak Road another 2 mi until you appear to be near the top (i.e. you can't see any higher spot a reasonable distance to the north) and you will encounter a short cutoff to the east which will lead you to the summit proper.
