The Victorian Era is famous, or infamous, for a number of peculiarities. What's been called--rather uneasily, I think--"Muscular Christianity" is one of them, or so I believe.
"Muscular Christianity" is the name of a movement of sorts which associates Christianity with physical exercise, physical health, team sports and such, not of humans generally but of men specifically. It's a very if not exclusively manly Christianity. Ostentatiously manly, in fact.
It's said to have had its genesis, as it were, in British authors like Charles Kingsely and Thomas Hughes. Hughes, it may be remembered, was the author of Tom Brown's Schooldays, a kind of celebration of the life experienced by boys in the English public schools of the time. Hughes, his book and his hero were spoofed by George MacDonald Fraser in his wonderful series of books which were the supposed memoirs of Harry Flashman, a rogue and scoundrel who, in Hughes' book, also attended Rugby when Tom Brown was there until expelled for drunkenness. Frasier's Flashman manages to be present at virtually all significant event of the era and though he's a coward and reprobate also thrives, and is in fact honored.
In the U.S., this form of pious muscularity has been associated with Teddy Roosevelt (called "The Great American Sissy" by Gore Vidal, by the way) and the YMCA. It's adherents seem to maintain that this kind or brand of Christianity looks back to medieval chivalry in that it champions protection of the weak by the strong, and it's been claimed that it has a basis in Scripture.
This seems dubious. From what I've read, the story of Jesus' anger at the money changers is considered scriptural authority or sanction for "Muscular Christianity." It's beyond dispute that muscles were required to tip over the tables of the money changers (unless Jesus, being God after all, and so not required to make use of muscles, threw them about by other means). However, Jesus presumably used his muscles for most everything he did as a man, and that's the case with normal men as well. So the use of muscles in and of itself would not seem to be peculiarly Christian or Christ-like.
It would seem then that what is considered important by Muscular Christians is the manner in which Jesus used his muscles in this case; that is to say, violently. But if violent conduct, even righteous violent conduct, is what's being touted there are difficulties with contending that this is what Christianity is or should be. According to the Gospels, Jesus was a great fan of nonviolence, as in turning the other cheek for example. Paul's references to athletic events are also referred to, but the ancient pagans often used such events as analogies even when philosophizing, e.g. Epictetus.
If ancient times or early Christianity are to be considered, it's much easier to find evidence of Muscular Pagans than Muscular Christians. Most Christians refused to even serve in the Roman military, at least until Christians began to become prevalent in the imperial administration. They condemned the Roman games. The early Christians could hardly be said to have emphasized the perfection and beauty of the human body. They were more likely to complain of it and damn it as sinful. Ascetics were idolized by early Christians, not athletes.
Of course, in the 19th century it would have been difficult for most in England and America to think of physical exercise of any kind as being anything but a manly pursuit. Women who engaged in it were likely considered odd, abnormal in a particularly disturbing way. So to the extent physical activity of the kind involved in sports, hunting or war were deemed religious activities or thought to be activities which could be engaged in for religious reasons, it's unsurprising that it was taken for granted that the actors would be men.
But the idea of manly Christianity as a special, better kind of Christianity, or of Christianity as being a manly religion, seems rather odd these days; even risible, in fact. For someone like me, alas, the old SNL skit about the good ship The Raging Queen and the manly ports at which it called comes to mind whenever the word "manly" is used. The relationship between Muscular Christianity and idealization of English public schools (and the YMCA at least as portrayed in a certain popular song) similarly encourages association with a particular kind of manliness, one which may be seen now and then when the female and the feminine are absent from the life being lived. It was arguably very much on display in ancient Greece, where women simply had no place in social life. But perhaps I'm too inclined to mockery.
Assuming I am too much so inclined, though, I still think the idea of a Muscular Jesus, exercising regularly, engaged in roughhousing and wrestling or whatever sports were popular at the time in Palestine, to be untenable. Romans of the time, at least of a particular age, regularly patronized the public baths in which it was common for these activities to take place, but Christians weren't known to frequent the baths any more than they did the ludi.
Muscular Christianity, then, has nothing to do with early Christianity. I think it likely it has much to do with Victorian values, instead, certain of which remain significant to some even in these times. I suspect that there is behind it a belief that certain kinds of physical exertion serve to keep the mind occupied and so incapable of erring in other ways; the idle mind being the Devil's playground. It may also be thought to channel physical exertions away from our base sexual urges and into something more desirable, something which requires discipline and conformity, like sports or, if appropriate, war.