I read something the other day that I actually tried to apply back in 2008-2010 when I was actually kinda fast. Id’ like to credit the coach and quote it verbatim, but I can’t relocate the recommendation so I’ll just paraphrase:
Try to add an additional hour’s sleep for every 10 hours/week of training. So 10hrs/wk = +1 hours, 15 hrs/wk = + 1.5 hours, 20hrs/wk = +2 additional hours per night. I know it sounds simplistic, and I can’t reduce my best-ever performance at that time to any single training manipulation, but I can tell you that I seldom, if ever, got sick or injured during my higher-volume training blocks (which, for the record, never exceeded 15 hours/week).