Not to mention that it was not uncommon to select those who would be wearing armour on the battlefield when young and get them to carry weights on their body and train so that they are used to it. I once saw a reenactor do cartwheels and I doubt he had training since his youth.
Was the armor theatrical armor or real armor? A lot of the armor made these days is just for show, often times far thinner than real armor is, or even made out of aluminum instead which is much lighter than steel.
SCA guys vary hugely. Some of them put in a huge amount of effort to make sure everything is as accurate as possible, made authentically and real. The swords and armor they make and wield could be used on the battlefield 500 years ago. Then you have the guys who just do it for appearances, but the stuff isn't actually functional.
Squires also had a really hard life. People back then were much stronger than today almost entirely because people back then could not sit in front of a computer screen all day long. The current generation is a bunch of flabby lardasses compared to the people back then. Sure, sure, if you were part of the nobility you were probably quite fat, but your average lower class who had to work for a living, including squires who were in training to be knights/men-at-arms (they were really the only ones who got to wear armor) would be doing hard work from about 8 years old on.
Remember what the Wikipedia article said? Well-made medieval armor weighs
LESS THAN MODERN COMBAT ARMOR.So, anything that a modern soldier could do when all suited up, a fully armored knight could do too.
Also, most of the armor back then was actually
bulletproof! The reason why knights went out of style was because you could make a musket in a couple of weeks and train a man to wield it in less, but a full suit of plate mail took
YEARS to build and had the relative cost of a battle tank today.
Battles were won and lost by the masses of foot troops: shoot enough bullets at a guy, and one's sure to find the eye slit.