After a lot of discussion about this on TPIN a few months back, I have been investigating and experimenting, trying to find the optimum ratio between practice / rest. I was surprised that it is more like 2 minutes on 40 -60 sec off !
It sounds crazy but it really works.
Set up a timer ( I use my CD player display ) and stick to this. You will see the improvement in just a week.
Practice anything you want, as hard or high as you want but quit after
2 mins. (I do some breathing exercises, or sing
the etude etc. in the break) I found I can practice ALL DAY, with a great sound pushing the envelope, yet still be mentally
and physically fresh day after day by practicing this way. Plus make significant progress as the weeks go by.
Now when I go out and do gigs I just forget about this and blow like there is no tomorrow and then take the next day off, but then it's back to the 2 minute routine.
My teachers used to say that I was "too keen" and that I was tearing it down instead of building it up. Now I now what they meant !
So check this out. I know this is the best thing I have done in years !
Peter Kartu, Sydney Australia