I am running a marathon, not a sprint, so I frame my long working hours within a “healthy schedule”. My typical day:
7:00 am - immediately start coding last night's plan, then email, headlines
8 to 9 - exercise
9 - breakfast & internet
9:30 to 12 - code
12 - lunch & internet
12:30 to 6 - code
6 - dinner with family (home or restaurant)
7 to 9 - code
9 to 11 - computer off, pencil/paper, analysis, design, detail plan for tomorrow
Exceptions: one to two days per week consulting (still keep my night schedule), one day per week with family, occasional sports on TV. I could keep this up forever.