Come to find out, a lot! I tried one workout last Friday after I got back from walking. Usually I do some crunches, lift a few weights, and stretch after getting back from my walk, so I figured why not choose one of these workouts instead? I did one for buns and thighs, and it felt pretty good, but, really - 10 minutes? But boy was I sore the next morning!
Yesterday I did three different workouts, and today I'm really sore. Of course, it's a good sore which tells me I actually did something, and it also tells me that I need to mix my workouts up a bit more and work different muscles. I guess I'm just going to have to try out all the different workouts!