I haven't run many 24 hour races, but I feel confident in my race strategy. The three keys are pace, diet, and body temperature.
I find an aerobic pace that allows me to run as efficiently and with as little extra movement as possible. This will allow me to put little stress on my stomach which allows me to digest food and put less stress on those running muscles to delay the build-up of lactic acid.
I like to alternate salt, fat, and sugar every twenty minutes or so. I prefer eating more often as opposed to a lot every hour. This has worked for me and keeps my energy levels pretty even the duration of the race. Vespa every two hours is key also.
As nighttime draws near, putting on the right clothing is key. Keeping your core temperature consistent keeps the blood flow to the muscles and stomach which need it. When you get hot or cold the body diverts some of your blood flow to deal with regulating your body temperature.
Lastly, I have found that running more and walking less keeps me looser and more uccessful. I thought mixing in walking early would help rest my running muscles and help me late in the race, however I found it did the opposite. Finding a pace I could run a long with was the key.
At Across the Years, I'm going to build in a faster paced ile every ten miles to help with the lactic acid build up.....I will let you know how it goes.
I hope this helps.