So, help me understand this please.

Two hours of practice a day is optimal. And a 35-40 hour workweek for information workers is optimal (from other sources, not the Ericsson study.)

I assume that if one deliberately practices, there is less willpower left to work, reducing the effective workweek by about 10 hours to 25-30. That is not sustainable for a normal person. The exception would be if the skill practiced used different parts of the body and mind than the work. For example, practicing basketball while working a programming job.

Do I have that right?