Medieval armour was very heavy and caused wearers to use more energy, but many with the heaviest armour were on horseback.
ScienceDaily (July 26, 2011) — The French may have had a better chance at the Battle of Agincourt had they not been weighed down by heavy body armour, say researchers.
A study published July 19 in Proceedings of the Royal Society B shows that soldiers carrying armour in Medieval times would have been using more than twice the amount of energy had they not been wearing it. This is the first clear experimental evidence of the limitations of wearing Medieval armour on a soldier's performance.
During warfare in the 15th century, soldiers wore steel plate armour, typically weighing 30-50kg. It is thought this may have been a contributing factor in whether an army won or lost a battle.
"We found that carrying this kind of load spread across the body requires a lot more energy than carrying the same weight in a backpack," says lead researcher, Dr Graham Askew from the University of Leeds Faculty of Biological Sciences. "This is because, in a suit of armour, the limbs are loaded with weight, which means it takes more effort to swing them with each stride. If you're wearing a backpack, the weight is all in one place and swinging the limbs is easier."