Here the question is to see physical force (size, muscle) is the same as sexuality. In the men, usually, unless you have specific physical problem, both factors are united. The size and musculature give to the man the strength and stamina to be a powerful sexfighter. It is also a support high levels of testosterone, common in men fitness practitioners. In a girl, Im not so sure that muscle and size and are a benefit for "sexuality". It's just a personal opinion based on experience, of course.