sustainable thesaurus. Retrieved October 19, 2015, from http://www.powerthesaurus.org/sustainable/synonyms.
the mass of the object determines the amount of inertia in an object. Mass determines the amount of inertia an object has. It is an object's intrinsic property to resist change. the two main things are speed and velocity. You have to factor in a bunch of smaller things too, but those don't really have much effect.
The exact force required depends on the size and weight of the hoop, as well as the size of your waist. Inertia contributes a helping hand and enables the hoop to continue its angular momentum after your initial application of force, but not for long.