Muscle tees are basically tank tops with long arm holds. This shirt can be worn with a bandeau or a one or two piece bathing suit. These types of summer shirts are mostly found in three main stores which are Delia's, Forever 21, Victoria's Secret, PINK, and Wet Seal. They can have designs or can be a plain solid color. This can be a simple D.I.Y (do it yourself) project. Here is a picture of a bandeau and a muscle tee:
Bandeau With An Open Back Muscle Tee
Interested In Purchasing Anytime Soon?
Victoria's Secret- http://search2.victoriassecret.com/?q=muscle+tee&view=desktop&theme=vs
Forever 21- http://www.forever21.com/Search/SearchResult.aspx?dsNav=Ntk:primary%7cmuscle+tee%7c3%7c,Ny:True,Ro:0,Up:regular&dsDimensionSearch=D:muscle+tee,Dxm:AllPartial,Dxp:3&dsCompoundDimensionSearch=D:muscle+tee,Dxm:AllPartial,Dxp:3&br=f21&utm_medium=cpc&utm_source=google&utm_term=forever+21&utm_campaign=f21_branded_e&utm_content=g_40793879358_e_1t1&category=&gclid=clzr_l-5pl0cfavqogodtbcajw&keyword=muscle+tee&fromsearch=true
Wet Seal- http://www.wetseal.com/Search?q=muscle%20tee