On a Sunday morning, both Waldo Canyon and Barr Trail (east side Pikes Peak trail) are likely to be fairly crowded. For short hikes/runs, there is a trail about 20 minutes west of Waldo Canyon that I like due to small crowds. It doesn't have the elevation gain of Waldo, but starts around 9,500' and tops out around 10,000' (I'm guessing here). It's also a bit shorter than Waldo if you stay to the trail, but you can hook up with other trails and go as far as you want (it connects to the Loop the Peak 'trail', so you could go for a couple days).
To get there, go past Woodland Park on Highway 24. Just out of town, you go up a fairly steep hill with a small hospital on your left. About 1/2 mile past the top of the hill, turn left onto Edlowe Road. (It is a fairly major road. First one with a turn lane you come to after the hill.) Follow Edlowe to the end and park at the lot just outside of the gate at the Catamount Institute.