If you work 9 hours a day, exercise for an hour, commute for an hour, and sleep 8 hours, you're left with 5 hours every day.

Real-world tasks that fill those remaining 5 hours - Showering and getting dressed - Working overtime - Eating meals - Random errands and appointments - Shopping for food and preparing meals (could be off-loaded to the weekend)

It seems like you should be able to cram that stuff into 5 hours a day.

I think another factor the OP doesn't factor is time spent with a significant other. This varies from relationship to relationship, or family to family, but the expectations to spend time together can be quite high, and that can cut into personal productivity.