Once we sell out of our first batch of shirts (produced after 2 years of research and development), we will accumulate all the notes and come up with the final sizing. For now, if you like a tight and tapered fit, go with the athletic fit! We suggest true size, but if you like the tapered but want to wear it a little loose, size up. If you like a loose fit in general, go with the Journey Fit™. We suggest going true to size if you want it to be a more comfortable fit or size down if you want it to hug but not squeeze (it doesn't taper in).