Eli5 why someone is heavier when they are limp versus when they have muscle tension

Question

Eli5 why someone is heavier when they are limp versus when they have muscle tension

In: 21

Answer 1

It’s not about weight, it’s about center of gravity. The human body is fairly fluid, so when it is limp the center of gravity changes all the time- think of it like trying to carry a bag of water. When the person maintains tension, they automatically adjust their center of gravity to match that of the person carrying them. It makes them much easier to control and maneuver, and we perceive that as “lighter” because we have to engage fewer muscles to move them around.