Is running 180 steps per minute the best stride rate?
Not according to Steve Magness at Science of Running.
His basic premise is that there are two ways to increase speed while running. You can either increase your stride rate (steps/minute) or stride length (inches/step). Conventional wisdom, dating back to Dr. Jack Daniels, is that you should only do the latter and run at a constant stride rate. That rate happens to be about 180, and is based on Daniels's personal observations.
However, Magness uses empirical data to demonstrate that runners increase both when they run faster, and runners who only increase length are artificially limiting themselves. Runners can also increase one factor to correct the other. For example, runners who wear big, bulky shoes are likely to overstride and strike the ground with their heels. They can increase their rate to shorten their stride and smooth out their form.
My take: I haven't done the empirical research like Magness has, but I'm buying what he says. I know from personal experience that when I run hard down a hill, my stride rate and length increase to compensate for the assist I'm getting from gravity.
Also, I happen to run lightly and step quickly. When I started running ultras, I transformed by running technique by increasing my stride rate (and the cost of stride length). I did this because the racing flats I ran in required me to take light, quick steps and running in them full-time reinforced this habit.
Is running negative or even splits the only correct way to race?
Not according to former 100-mile world record holder Cavin Woodward. Ian Sharman (new Rocky Raccoon 100 course record holder, who ran even 20-mile splits) gets the hat-tip for linking me to the 1975 Tipton 100 track race.
I'll just quote Ian:
In the race described, Cavin Woodward [. . .] set the world best time at that point for 100 miles in 11:38, but it's the way he did it that amazed me. He ran 2:31 for the marathon, 3:01 for 50k, a world best for 50 miles (4:58) and a world best for 100k (6:25)!It's just nuts. Woodward finished at 11:38:54. He ran the first 50 in just under 5 hours, and the second 50 in six hours and 40 minutes. That's a huge pace drift, but he won the race and set three world records in the process.
The post at UltraLegends lists the 10-mile and 50-mile splits for the four fastest 100 mile times (including Woodward's race above). The format is not reader-friendly, and UltraStu put them into a table.
The table shows that it is not necessary to run even or negative splits to do well. You just need to go out hard enough to put up a good time and then taper off just enough to hold onto your time goal and hold off your opponents. The idea is that everyone slows down over time, so why not run hard when you're fresh? It makes a compelling argument, especially given Woodward's accomplishment above.
My take: I try to run even or negative splits in ultras, and I measure this by effort (and often, but not necessarily, pace). I do this because it feels better to me. I get a constant effort, and I don't feel like I went out too hard and lost it all in the end. Running even splits is more comfortable to me, and it is a goal I strive for in every race. Until that comfort level changes or I am looking for a speed boost, I'm going to stick with what works.