Hmm you are wrong there. In Africa there are certain tribes that have muscular men. Men from Nigeria,ghana,ivory coast, and Cameroon tend to be muscular while men from Sudan and Senegal tent to be either tall and sender or tall and muscular. Men from central Africa can be muscular if they have west african origins(people like serge ibaka or mutombo). If they don't have west african origins (like the mouth pygmies of congo) then they are usually short and stocky... or frail. Most black people from the Americas come from the muscular west african countries that I listed so this gives the illusion that black people can gain muscle easily. Black people from east africa,south africa, and parts of central Africa tendo to not be muscular though. The same applies to white people. White people of northern European descent tend to be really strong (people from Scandinavia,germnay,austria,netherlands and the uk).