[RTTY] Staying Alert in 48 hour contests

[Don AA5AU]

I'm thinking I'm going to have a hard time staying alert for the CQWW RTTY Contest.  Since I didn't operate this contest last year, I have no idea how I'm going to react on little sleep.  I'm a big fan of sleep.  The most I ever operated this contest was 44 hours in 1999 and that was only because 20 meters was open to EU all night that year.  I've noticed that 20 meters has been open all night to EU a lot here lately.  If that's the case this year, I may have to operate more hours than I had hoped.  My plan is to sleep 4 hours each night.  Even if I do that, I'm afraid I won't be fully alert toward the end.
 
A few years ago I switched from Coca Cola to Diet Coke in order to cut down on my sugar content (I have high blood sugar but not diabetic).  I also like to consume a BC Powder every six hours or so to prevent headaches and to get some caffeine going.  The problem with that is that when it's time to rest, the caffeine in the BC powder, combined with being jacked up for the contest makes it hard to go to sleep even though I'm physically very tired.  I've never been a big coffee drinker and actually have quit drinking coffee all together.  Prescription drugs are out of the question.  One thing that helps me (I think) is that I tend not to eat big meals during contests.  I'm not a big eater anyway.
 
Recently I tried "5 Hour Energy" a couple of times when I was feeling tired at work and it really picked me up.  I'm thinking about getting a few of those and trying them during the contest.  The manufacturer recommends no more than two drinks a day which means I could do the whole contest on four shots (they aren't cheap).  I know there are tons of energy drinks on the market today.  I'm wondering how many contesters might be using them and if so, which ones might work best.  I'm wondering what others do to stay awake and alert during iron man contests like CQWW RTTY?
 
I certainly don't want to fall asleep at the keyboard with the auto-CQ going as one prominent contester did recently. HI HI
 
73, Don AA5AU