Here is an article from 1979 that I wish everyone, especially opera haters, would read.
Opera singers, athletes? Those paranoid, overpampered, overweight bags of air who won’t go outside for fear of catching a cold, who speak in monosyllables for fear of tiring their voices, who flee the room when someone takes out a cigarette? Dancers, yes, now they could be called athletes. After all, they move around, they even pick people up. But singers?
People speak of a singer’s musicality, his subtle phrasing, his feeling for a song. Never do they mention his athletic ability. And even when they speak of a singer’s power, they don’t usually equate it with physical strength. But the fact is, opera is extremely demanding physically, and a good opera singer must possess many of the same qualities as other good athletes: strength, coordination, stamina. His playing field may be a stage, his uniform a fancy costume and his warmup suit a five-foot scarf, but a singer is, in his way, as much an athlete as Terry Bradshaw or Reggie Jackson.
The article goes into quite a bit of detail about the physical demands of operatic singing. Again, I wish everyone in the world would read this. Honestly, I don’t expect everyone to like opera. Different strokes for different folks as they say. But when people dismiss opera as “nothing but a lot of screaming and bellowing” that is just as wrong, fundamentally dishonest and inexcusable as it would be if I said baseball players are not athletes because they spend a lot of time just standing around. You can recognize the skill and talent even if you don’t like the end result.