Dr. David Nieman is a top researcher and is often quoted in major publications like the New York Times (check out http://well.blogs.nytimes.com/2012/06/20/can-athletes-perform-well-on-a-vegan-diet/)
Nieman was also highly involved with research related to the Western States 100 mile endurance run. I contacted Dr. Nieman regarding weight vs. performance and he was kind enough to send me a summary of his Western States work. Check out the following, inclusive of a wild formula to predict one's finishing time for 100 mile racing!
In general, the data indicate that these runners (age range, 19 to 69 years) were deeply committed to training for and competing in ultra-marathons. A stepwise, multiple regression model showed that the 160-km WSER race time (h) could be predicted by this equation: 12.57 + (0.126 x age) + (2.56 x gender) + (0.285 x BMI) – (0.01931 x km/week) (R2 = 0.23) (male gender=1, female=2). Thus race time for a 20 yr old male with a 22.0 BMI, and a training distance of 130 km/wk would be estimated at 21.4 h compared to 28.5 h for a 55 year-old male with a 27 BMI and 65 km/wk training distance.
Here's how my formula looks:
12.57+(.126*55)+(2.56*1)+(.285*21.5)-(.01931*112.65) = 26.0122285
Wow. I had a 24:32 about 15 years ago. So based on my BMI, age and weekly miles, science says I can crack out a 26 hour run. Thanks Dr. Nieman. That's the bump I needed coming off today's body slam 10-miler in the heat.
Why don't some of you run your own numbers and post a comment? I'd like to hear about how you'll be doing at your next 100 mile attempt.