How to run 100 miles in 24 consecutive hours.
Running is a habit I feel I CAN do without. I want to quit. The problem is I can't stop. I run almost nightly - in the fall, I run 6 to 7 nights per week, sometimes doubling up on weekends. Running compromises my time with photography, family, and friends. 
10+ years ago, my goal was a "good" marathon time. "Good" is in the eye of the beholder, but I wanted to qualify for the Boston Marathon... that was my definition of "Good." The difficulty was that I did not have the patience nor persistence to put in the training required to accomplish the goal. I had the desire, but not the persistence to satisfy the desire.
What is an Ultra-Run?
Now, I am more persistent than ever.... I am also slower than ever. No problem - there's a sport to accomodate that - Ultrarunning. Ultra-runs are any event over 26.2 miles in length. Popular distances are 50k, 50 miles, 100k, and 100 miles. Additionally, potentially longer events exist - events that span fixed time periods, such as 24, 48, and 72 hours... even longer.
From an ultrarunning perspective, I am young and fast. 3 years ago, I ran my first 24 hour run at Nardini Manor in Litchfield Park, Arizona. It was the "Across the Years" run, and I was thrilled to run, walk, eat, and nap my way through 24 hours, while ringing in a new year.
What happened when I tried this before?
In my first effort, I traveled 66 miles in the 24 hour period. Although I was happy, the new goal was clear. The second year (2005), I managed 80 miles. The 80 was fun, but it didn't feel much better than the 66. I experienced what I can only describe as "multiple leg trauma" in both efforts. Quite simply, I was not going to be able to add 20+ miles with the same technique.
I made several goals / covenants for my 2006 training
1. Supplements. I now use Perpeteum as my primary sports drink and Endurolyte capsules as a supplement while running. See Hammer Nutrition for more information.
2. I now run with water. I purchased a Camelbak Flashflo hydration pack. The Flashflo differs from many other hydration packs, as it is worn as a belt, rather than a backpack. I drink approximately 45 oz of water from the Flashflo every two hours during training runs.
3. I doubled my 2005 mileage in 2006. No excuses for not working out. Very few workouts cut down from their originally planned distance.
When did I run?
I elected to run my 24 hour event on December 29th, 2006 at the annual Across the Years. Runners in the same 24 hour race have the option to start on the 29th, 30th, and 31st. Race time is 9am to 9am. Also, on day 1, the 72 hour runners began their race, as well as the first opportunity 48 hour runners. Since the 48 and 72 hour runners double and triple the duration of the 24 hour race, 24 hour runners are sometimes referred to as the "sprinters" of the field.
How did it go?
It was surreal. I started at a measured pace - the tendancy is to start too fast - but the runners must remind themselves - they're going for 24 hours... possibly more. I maintained the pace and tediously stuck to my care and feeding schedule.
Some friends came to visit during the day and my family arrived in the early evening. In past years, I had been walking by early evening, occasionally running for awhile. This year, they just saw me run. And the running was at a good pace.
At 12 hours, I had 58 miles. I faced a period of uncertainty. My plan, conceived during hundreds of tedious running hours during the year, was to accomplish 60 miles at the 12 hour mark in order to assure 100 miles by the end. Yikes! I was behind plan! My legs still had plenty of life and I persisted.
This is the first time that I was 'clicking' this far into an ultra-run. I was only part way to my goal, but I could taste it. Visions of various past runs, from junior high through present-day faded through my head... both victories and disappointments.
The next checkpoint would be 3am. I determined that most runners that run 100 miles in 24 hours have 80 miles by 3am. Success! I had over 81 miles at 3am. At this point, I was walking a measured portion of each mile due to fatigue. However, I was frequently cutting the walking periods short - therefore running more than planned. By 4am, I was positioned to complete 100 by moving forward at 3mph. That was good news, because I was continuing on at a pace just over 4.5 mph.
At 7:55am, I accomplished the distance of 100 miles. I sat briefly in my course-side patio chair, and then added another 2.8 miles to the total mileage, to finish with 102.8. Two days later, after two more sets of finishers, I would learn that I was the top-finishing open-division male and captured 5th place overall. Exceeding 100 miles earned a belt buckle.
Next Year
With a 100 mile performance under my belt, I am looking forward to less pressure next year. In the second half of this year's run, I had to proceed conservatively, as not to jeopardize a 100 mile finish. Next year - no caution... I will go as fast as possible all night.