Jeremy I definitly have been thinking about this. You inspired me to do a video in response to this. 
You are helping me clarify my standpoint. I do agree with you that when you are a coach “It depends” is usually the right answer to generic high level questions. I think when you are a self-coached athlete that is not an expert it needs to be more simple. I am working on my perspective and a evidence based but simple perspective answer. I also may sound like I am really pushing Polarized training but the reality is I agree with “It depends.” I hope my video will help simplify peoples decision process on what to do.