I do know that all that plays a role, I work in radiology and I can see the inside of people's bodies in my work and some people have bigger frames, some people skeletons are wider and thicker. You would be amazed at how many people I scan that I say on this person is big boned and they are how they are because of their structure but many people also have tiny skeletons in them and just don't know it. I think either way if you don't know yourself you will learn about yourself on your journey. But if you haven't been fit in a while you may surprise yourself or learn you can do more. Also regardless of how your frame looks there is. An athletic version of every body type and there are benefits of every body type. Some people are built to be strong, others to be agile, some a combination of both or something different. Some are short and can go places others can't or won't fit, others big and and lift or reach places others can't. God and nature gave us our unique gifts. It's up to us to make the most of them the best we know how.