It is in chapter 9 that Kunitz introduces his most pioneering argument: the feminist movement changed the face of fitness. As Bonnie Prudden and Jack LaLanne continued their campaign, they promoted calisthenics to women around the nation, appealing to the notions that the point of exercise was beautification and the maintenance of family health fell under the umbrella of “women’s work.” However, these exercises were still restricted to light work. When Thomas Cureton published his book The Healthy Life: How Diet and Exercise Affect Your Heart and Vigor, awareness was brought to the fact all people of all ages—including working men—need to exercise. Similarly, in 1968, Dr. Kenneth Cooper published his influential Aerobics which ignited a jogging trend in the United States and abroad. However, Kunitz argues this landmark book is only part of the story of increase in mass participation in exercise during the 1960s; instead, the influence of the feminist movement deserves the majority of the credit. As women rebelled against all sorts of social structures, more vigorous workouts were not excluded. Women revolted against the idea that they were not to run long distances by officially entering marathons, leading to an increase in participation from other females as well as attracting more men. It is in this argument that Kunitz again shows fitness as a political instrument and mirror of culture. Empowered by the feminist movement, women like Lucille Roberts and Jacki Sorensen opened all-female gyms and launched new forms of exercise, including Jazzercise. In turn, more and more women found themselves in gyms and fitness classes. It was Jane Fonda who popularized aerobics even further by bringing these activities past the gym and into the homes of women across America. Kunitz asserts that gyms existed for decades, but a swell in participation could not and did not occur until the women’s liberation movement.