News has come out over the last few days that the McMillan Running Calculator, the simple and effective training and goal-setting tool, has undergone some tweaks. The ranges given for workout paces have been widened, and most notably, predicted finish times have been added for distances beyond 26.2 miles.
Hey, I love the calculator, it's incredibly accurate and useful... but this update is just goofy. As the site plainly admits in all the disclaimers lower on the page that you don't read, there are so many variables with ultras that even attempting to extrapolate a finish time based on other results is a futile exercise.
Ultras take muscular endurance to a whole new level. They are emotionally taxing. And most of them are as unique as fingerprints. So telling someone, "Well, you ran a marathon in X time so you should finish a 100 in Y," is setting an unreasonable expectation that will only cause a letdown when it goes unmet.
Take my numbers for instance. I plugged in my time from my last race, 1:02:52 for 15K. The calculator says I should have a 5K time of 19:32, and my 5K PR is 19:23. The calculator says I should finish a half marathon in 1:30:28, and my PR is 1:29:51. So far, so good.
At the marathon distance, the numbers break down a little, as now you're getting into the body's physiological changes that the calculator can't account for (e.g., the depletion of stored glycogen). McMillan has me at 3:10:23, fully 2 1/2 minutes below my PR. It's not way off, but it's off, at least until I take a shot at 3:10 in Houston in January.
After that, it gets wacky. Fifty miles in 7:02? That would put me in the top 30 at JFK or the top 20 at American River. As it stands I'm good for 10 hours. With a lot of work and experience, maybe I can crack 9 in time. But a breath over 7 hours? Not in a million years. And at 100 miles, the calculator says 18:19. That figure is so invalid it's not even worth discussing.
I appreciate McMillan trying to innovate and cast a wider net, but this is very similar to Accuweather moving to 25-day forecasts on its website. It's fun to speculate and set goals, but these projections should be used for entertainment purposes only, not actual targets.