Muscular Body Ideal
One potential explanation of the drive for muscularity in men may be objectification theory. Western culture emphasizes muscular mesomorph for men, by reinforcing the connection between muscularity and masculinity (McCreary & Sasse, 2000). Men are similarly exposed to images and are encouraged to achieve the body ideals valued by Western culture (Daniel, Bridges, & Martens, 2014)
Direct quote from: https://openworks.wooster.edu/cgi/viewcontent.cgi?article=10132&context=independentstudy