Title VII
So long as there is an equal burden of compliance and the same level of fitness is demonstrated by the varying standards, gender-specific physical fitness guidelines do not violate Title VII.
http://www.ca4.uscourts.gov/Opinions/Published/142323.P.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.