"Long before it's in the papers"
January 27, 2015


Suits of armor take heavy toll on wearers, study finds

July 20, 2011
Courtesy of the University of Leeds
and World Science staff

If you think an aer­obic work­out is tough, ima­gine doing it in a full suit of ar­mor.

Many me­die­val sol­diers en­dured such exer­tions re­gu­larly, of course. A new study has found that the heavy met­al prot­ecti­on took a steep toll on in­creas­ingly tired fight­ers—forc­ing them to spend about twice the nor­mal amount of en­er­gy just to walk or run, all while hav­ing to breathe a bit un­nat­ural­ly.

An ex­per­i­ment­ works out wear­ing ar­mor. (Cour­te­sy of the Uni­ver­si­ty of Leeds )

Sci­en­tists claim the find­ings may af­fect our un­der­stand­ing of some long-past bat­tles.

“Ar­mour de­sign re­flected a trade-off be­tween pro­tec­tion and mo­bil­ity,” re­search­ers not­ed, re­port­ing their find­ings in the July 20 ad­vance on­line is­sue of the re­search jour­nal Pro­ceed­ings of the Roy­al So­ci­e­ty B. “By the fif­teenth cen­tu­ry, a typ­i­cal suit of field ar­mour weighed be­tween 30 and 50 kg (70 to 110 lbs)” of steel plate.

How this weight af­fected war­riors’ per­for­mance has been lit­tle un­der­stood, they added.

“Car­ry­ing this kind of load spread across the body re­quires a lot more en­er­gy than car­ry­ing the same weight in a back­pack,” re­marked bi­ol­o­gist Gra­ham Askew of the Uni­vers­ity of Leeds, U.K., lead re­searcher in the proj­ect. “In a suit of ar­mor, 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.”

Askew and col­leagues worked with fight in­ter­preters from the U.K.’s Roy­al Ar­mour­ies Mu­se­um, who wore ex­act repli­cas of four dif­fer­ent types of Eu­ro­pe­an ar­mor. Us­ing tread­mills, they un­der­took a range of walk­ing and run­ning ex­er­cises while their ox­y­gen us­age was meas­ured, as an in­di­ca­tor of en­er­gy ex­pend­i­ture.

De­tail from The Bat­tle of Or­sha, an early-16th cen­tu­ry picture of a Pol­ish bat­tle be­lieved by art his­to­ri­ans to have been paint­ed by one of its par­tic­i­pants. The de­tailed de­pic­tion in­cludes such life­like scenes as sol­diers re­mov­ing their ar­mor to pour out the wa­ter af­ter a riv­er cross­ing (see full im­age here.) (Na­tion­al Mu­se­um in War­saw)

Par­tic­u­larly trou­bling for knights must have been that the ar­mor re­stricts free­dom in breath­ing, the re­search­ers found. Rath­er than tak­ing deep breaths while ex­ert­ing them­selves—as they would have nor­mally—the ar­mored ex­peri­ment­ers took shal­lower, quick­er breaths.

“Be­ing wrapped in a tight shell of ar­mor may have made sol­diers feel safe, but you feel breath­less as soon as you beg­in to move around in me­di­e­val ar­mour and this would likely lim­it a sol­dier’s re­sist­ance to fight,” said co-invest­iga­tor Fe­de­ri­co For­menti of the Uni­vers­ity of Auck­land, New Zea­land.

The find­ings “can pre­dict age-associated de­cline in Me­di­e­val sol­diers’ phys­i­cal per­for­mance, and have po­ten­tial im­plica­t­ions in un­der­stand­ing the out­comes of past Eu­ro­pe­an mil­i­tary bat­tles,” the re­search­ers wrote in the re­port.

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Medieval suits of armor forced their wearers to use about twice as much energy just to walk or run as they would have otherwise, according to a new study. Scientists claim the new findings about the hard limitations imposed by medieval armor may affect our understanding of some long-past battles. “Armour design reflected a trade-off between protection and mobility,” researchers noted, reporting their findings in the July 20 advance online issue of the research journal Proceedings of the Royal Society B. “By the fifteenth century, a typical suit of field armour weighed between 30 and 50 kg (70 to 110 lbs).” But how this weight affected warriors’ performance has been little understood, they added. “Carrying this kind of load spread across the body requires a lot more energy than carrying the same weight in a backpack,” remarked biologist Graham Askew of the University of Leeds, U.K., lead researcher in the project. “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.” Askew and colleagues worked with fight interpreters from the U.K.’s Royal Armouries Museum, who wore exact replicas of four different types of European armour. Using treadmills, they undertook a range of walking and running exercises while their oxygen usage was measured, as an indicator of energy expenditure. Particularly troubling for knights must have been that the armor restricts freedom in breathing, the researchers found. Rather than taking deep breaths when they were exerting themselves—as they would have done had they not been wearing armour—the interpreters took a greater number of shallower breaths. “Being wrapped in a tight shell of armour may have made soldiers feel safe, but you feel breathless as soon as you begin to move around in medieval armour and this would likely limit a soldier’s resistance to fight,” said co-investigator Federico Formenti from the University of Auckland, New Zealand. The findings “can predict age-associated decline in Medieval soldiers’ physical performance, and have potential implications in understanding the outcomes of past European military battles,” the researchers wrote in the report.