I wouldn't say we "speed" walk, but we do keep a quick pace. Just fast enough to sweat (from the walk, not the temp) and kinda jargle our speech. We walk 2 miles in about a half hours time. It was the only cardio Mike did to prep for his show and that with diet and weight training ... he lost 70 pounds in about 3-4 months.
Thats amazing Cheri!! Wifey and I take O dog a few miles every night, all I need to do is start lifting again and adopt the Adonis principals