1. What is the purpose of the bend test?

The main purpose of the Bend testing is to determine the ductility, bend strength, fracture strength and resistance to fracture of the specimen i.e the characteristics used to determine whether a material will fail under pressure and are especially important in any construction process involving ductile materials

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.