Many exercise enthusiasts have thrashed their knee joints by running endless miles on concrete roads. Many of those exercisers either quit or turn to cycling, but a small number take up fitness walking or even race walking. Therese Iknoian, a nationally ranked race walker and fitness journalist, starts Walking Fast with the assumption that only people interested in her sport will pick the book up, so she's not trying to "sell" the sport. Iknoian discusses race-walking technique (you have to understand terms such as heel strike, toe lift, and pushoff) and clears up any misconceptions you may have about what a race walker's hips are doing in midstride. (Someone who has seen race walking only in the Olympics might assume that the hips are sashaying from left to right, like Marilyn Monroe's, when in fact it's a far more complex up-and-back motion that is best realized by imagining that your legs are an extension of your waist rather than your hips.) The benefits of learning the technique? Race walking is great exercise without much impact on your joints (there's never a point when both feet are off the ground, as in running). People who try the sport swear it's a blast, and there's a surprisingly large network of fellow walkers with whom to connect.