Answer:
Um... That you're sick? I have no clue... Are you looking for a specific illness?
To be physically fit it means to eat healthy and have at least 30 minutes or blood pumping cardiovascular exercise a day it does not mean to way a certain weight or look a certain way
I believe the correct answer would be actin filaments. These are polmers that are linear with G-actin as subunits that attaches ith myosin heads during the skeletal muscle contraction. They are necessary for cell shape, adhesion and contraction.