I have played poker now for about a decade and have been profitable in the 5 digits overall.....I would call my game strong intermediate though I don't play that high anymore bc I prefer live cash but don't live close to a tournament/have tonnes of opportunities to travel at this time.
I find for myself and most people i've known in poker playing 6-7 days a week is usually not going to lead to optimal play. There comes a point for MOST people that you kind of lose your edge, and that goes for hours within a day and also days within a given period....say a week or 2.
If I had to pinpoint an optimal amount of play for just results, i'd say 3-4 days a week for 5-8 hours with a break in there for a meal. Now that is for OPTIMAL ROI- best peak play. That doesn't mean the same as optimal EV overall; someone may make MORE money playing 60h a wk, but is will be a lower hourly imho in MOST CASES.
If I had to pinpoint an optimal amount of play for LEARNING SERIOUSLY, I would up it a bit and play around 5 to 6 days a week maybe 5-8 hours with a shorter session on the 6th day or something and at least one day of total rest from poker/stress thrown in.
As far as learning off the felt, I do think it can be helpful, but way too many beginners have come to believe it to be as important as play, and I THINK THIS IS A MISTAKE.
If the super optimal amount of play to be LEARNING SERIOUSLY is say 5 days a week for 7 hours and then 4 hours on the 6th day; I would only throw in maybe 6 hours of off the table learning, 8 at most to that regimen.
You simply get to a point where there is overload in how much info you are actually going to be able to assimilate efficiently. Watching one vid before bed or during a meal on your working/playing days and then 1/2 on you lower volume days seems reasonable. Maybe switching off from vids to HH review once a week makes sense also....maybe a bit more if you are losing.
The point is:
YOU HAVE TO PLAY A LOT OF HOLDEM TO GET BETTER AT HOLDEM.