<P> During the Cold War, a focus on physical fitness emerged in both the United States and the Soviet Union . Senator Hubert Humphrey gravely warned that communist dominance came from superior sports and fitness programs . His remarks reflected the growing American paranoia of communism . In response, leaders of the military, civilian government, and private sector began crafting a "cult and ritual of toughness". President John F. Kennedy issued a call to the nation urging Americans to prioritize their physical fitness across the country . Fitness was clearly described as a "matter of achieving an optimum state of well - being" that required exercise from both young and old . This focus on fitness also opened the doors for female athletes in both The U.S. and the USSR to become more prominent as contenders in the Olympics . </P> <P> After World War II, a new form of non-organized, individualistic, health - oriented physical and recreational activities such as jogging began to prevail . For instance, aerobics--a form of group gymnastic activity performed with the support of music--was developed in the 1970s . Gyms were set up with the goals not to improve public health but to stimulate and exploit the desire of people to keep fit, have fun and improve themselves . It can also be observed in today's gyms where bodybuilders are trying to reach their aesthetic ideas, through muscle development, using weights and other equipment . </P> <P> Nowadays, fitness has been commercialized . The term gym is often associated with the term fitness and going to gyms means doing exercises in fitness institutions such as fitness centres, health clubs or gym clubs where people have to pay for membership in order to use fitness equipment and participate in group fitness activities with instructors, such as aerobics and yoga classes . </P> <P> In addition, advances in technology have changed the way of doing fitness activities . Quantified Self becomes a new phenomenon, where people use technological devices to support their workouts . It is characterized by the use of gadgets such as pedometer, GPS, heart rate monitor and smartphone apps to quantify or monitor the exerciser's efforts . </P>

When did going to the gym became popular