I am currently studying Mandarin via Assimil Chinese with Ease. First of all, I have removed the pauses and created audio files with just one dialog each. This allows me to repeatedly go over the material 5 to 10 times instead of just once, in the same time span as the original files. I want to chorus with the audio of each lesson hundreds of times. I had intended to do each lesson for one hour each day and then move on to the next lesson the next day.
Well, it turns out that so much speaking is really strenuous on my vocal chords. I have discovered that I can only do this kind of intense activity for 5 minutes at a time. Then I need a couple of hours of rest. So, instead of an hour, I have only been doing about 10 minutes a night. I still want to spend an hour on each lesson, so it is taking 5 or 6 days per lesson now. At this rate, it will take me another 16 months to finish the course. I really do not want to go so slowly.
I think I could get 4~5 sessions done in a day. One before going to work. One during lunch. One as soon as I get home after work. Another one a couple of hours later. And a final one before I go to bed. That would make 20 to 25 minutes a day. But maybe that would still be too much for my throat and mouth. Muscles usually need a day to fully recover. It's like typing. Even though I use a computer all the time, everyday, I don't constantly type every minute. I type a bit and then think for awhile. I don't have any problem from this normal amount of use. But if I do data entry, then I will notice I can only do so much typing.