Does Walking Increase the Size of Your Legs?

I hit up the gym about three times a week or so, but the equipment is pretty sparse due to the fact that is within my apartment complex. Sure there are two treadmills, a bike, elliptical, and some free weights- but it’s nothing compared to the big chain gyms. I’ll take what I can get though, and rely on magazines and the internet to keep mixing up my workouts and giving me new ideas.
My only problem with the treadmill is that I don’t like to run. I have bad knees and a bad ankle from my cheerleading days in high school, so running for just a few minutes can cause me a lot of pain. To still get a good workout, I decided to take up walking. I started power walking but didn’t feel like I was getting too much out of it, so I switched to walking on an incline. And I have met my match. As of right now, I walk at a brisk pace, and slowly creep up the incline, until a reach a level 8. Once I get to that 8, I am winded, my legs are burning, and I feel like I may collapse on the treadmill, so after about three minutes I start to lower the incline again and eventually cool down. After I complete 30 minutes, I am drenched with sweat, my heart rate is definitely up, and my legs feel like jello. But I feel great, because I know I just gave myself a great workout.
I did get worried that by walking on an incline that I would actually be making my legs (especially my thighs) bigger and bulkier, but one click on the internet showed me that is not true. About.com gave a pretty straightforward answer on my dilemma, explaining that walking, along with a variety of other aerobic exercises, uses the body’s slow-twitch fibers, which are designed for sustained activity and will not grow in size. To get lean and toned legs, walking on an incline is highly recommended. To burn more calories, increase your speed or the incline or both! Good luck!