My job cyclically stresses us like that. The sailors will substitute being in good aerobic shape and sleep with the use of caffeine (coffee, tea, canned energy drinks) and nicotine (smoking, dipping)
Some of us bank sleep a little bit-it's not very effective, but lots of rest on teh weekends helps us get by on the weekdays when we actually get weekends off.
I think consuming high quantities of sugar gives you real dangerous lows that only help for a short while but hurt you over extended periods.
When I worked on a farm/ranch they made us eat oatmeal for breakfast claiming (and I believe) that it gives you better energy thru out the morning.
After all of the health training and experience, it really boils down to diet and exercise.
If you could train/discipline yourself, my grandfather managed to live off of 4 hours of sleep a day with lots of coffee and no aerobic exercise for many decades; But he had a minor heartattack at 50ish that could have killed him.
Choose your fate, once your not in your early twenties anymore, you can't just force your way thru it without consequences. Genetics and the health/in shape level you had in your youth influences it a lot as well.
