Why do men usually have stronger muscles than woman?

"Males remain stronger than females, when adjusting for differences in total body mass, due to the higher male muscle - mass to body-mass ratio. The greater muscle mass is reported to be due to a greater capacity for muscular hypertrophy as a result of higher levels of circulating testosterone in males."

Men and woman are built differently and it is all based on genes. So men can be not strong at all and the girl is built more ... like I said it all depends on the genes and person