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Martin Jenkins
London, UK
In 1916, British troops marched to the Battle of the Somme sporting packs that weighed about 30 kilograms. This is roughly the identical as a Sixteenth-century knight’s plate armour. However, this armour lined the entire physique and was designed to be versatile, so knights have been in a position to stroll and mount their horses. The troopers needed to load all the load on their backs and have been exhausted on arrival.
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It isn’t how a lot you’re carrying however how and the place you carry it that makes the distinction.
Nick Baker
Colchester, Essex, UK
Our skeletal geometry and muscular system has advanced to deal with our personal physique weight when sitting, standing and strolling. Excess physique weight tends to be added to particular areas, such because the trunk, waist and higher limbs, that are already the extra large components of the physique.
“Coping”, on this sense, means supporting the load with a minimal expenditure of vitality. This is achieved primarily by posture, in order that stresses on the physique are predominantly compressive and therefore transmitted to the inflexible bone of the skeleton, requiring solely minimal muscular motion to take care of steadiness.
In order to hold a weight, nevertheless, significantly when concentrated in a single, dense object, massive tensile forces are concerned. Muscles present these forces – the biceps, for instance, when carrying a pile of books – however they ultimately change into fatigued and point out this via emotions of discomfort and ache.
If the additional weight may be carried in such a manner as to extend solely the compressive forces taken by the skeleton (the backbone and the legs), then much less fatigue and discomfort outcomes. This, along with an upright posture, explains how some individuals can carry enormous hundreds on their heads.
The closest most of us get to that is sporting a well-designed rucksack, however even that requires a (much less elegant) change of posture to convey the centre of mass of the ensemble above the ft.
Chris Warman
Hinderwell, North Yorkshire, UK
If the correspondent had misplaced 15 kilograms quickly, this might result in muscle being misplaced at a quicker charge in contrast with longer-term weight-reduction plan. Under extreme calorie restriction, the physique makes use of glycogen from the muscle tissues and liver to offer the vitality to remain alive, making it weaker.
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