If you're looking for a moderate workout with gorgeous views of the Valley, Cholla Trail is for you. I visit this trail a handful of times each year... usually when I have company in town that is interested in hiking.
Cholla is the "easier" of the trails you can hike on Camelback Mountain. Echo Canyon is a lot more intense. Even so, you'll get a workout on either side...
I'm always sore after I hike Cholla since I do it so infrequently. I highly recommend doing an early morning sunrise hike... and regardless of what time of day you go, pack some water and wear your sunscreen. Trail shoes are best, but even if you've got those, be careful on some of those little loose rocks; I've seen plenty of people slip and fall on those.
Happy hiking!