But for me this does not work very well. For myself I have found that the optimum is attained by dividing the day into small sections. An hour of learning Talmud, an hour of Physics or Math, an hour exercise, etc.
To some degree this is based on Rav Shick with whom I was involved for a number of years. His idea of learning he based on an idea of the Talmud in Tracate Shabat 63a (say the words and go on) and also on this idea of what he called שיעורין כסדרן [sessions in order]. In modern Hebrew that would have to be called קביעויות sessions in order. [Because today the word "שיעור" means "class" as in giving a class].
At any rate, this idea originated with the Ari who said to learn every day a session in the Bible, a session in Mishna, a session in Gemara, and a session in Kabalah.
Spreading my learning I have found is better for me. But I can see that there are people that it would benefit to concentrate on one thing alone and by that to excel in it. But for me that never works. I tried it with the violin and I discovered "the law of limited returns." That is for me there is a low threshold of effort that crossing that threshold does nothing. The "law of limited returns," can be stated simply like this: There is certain number of times that kissing you wife will not add to marital bliss.
As for the violin practicing more that a certain amount hurt my playing--and my ears. As for Gemara learning I spent about 10 hours a day learning Gemara in NY two great Lithuanian yeshivas in NY.
But in that also there seems to have been a point that I reaching where more learning resulted in less.
The law of limited returns strikes back.