Fitness Industry history: Please list the group or groups of people that joined the fitness industry in each of the following "eras." A) 1940's and 50's______________

B) 1960's and 70's______________

C) 1980's______________________

D) 1990's______________________

What two changes occurred in society in the 1960's and 1970's that led to the above group joining the fitness industry? Please discuss how each change had an affect on sport and on the fitness industry?