There's also the value of the strength work. As Jay Dicharry, MPT, puts forth in his detailed examination of biomechanics and running, the excellent book, Anatomy for Runners, nothing drives him crazier in his practice then when a veteran runner comes into his office with a chronic injury (or injuries) and Dicharry asks what the runner has been doing as far as routine maintenance over the years, and and the answer is 'lots of running' and nothing more. To illustrate his point, Dicharry uses the metaphor of a car mechanic talking to a customer whose car is breaking down at 73,000 miles and reports that he never changed the oil, timing belt fixes, tire rotations etc. "Nope," the car owner says. "Just parked it in the garage and when it was time to go, expected it to run."
Dicharry's model is similar to MacKenzie's and to Kelly Starrett's: Correcting your movement errors is something you should do first rather than later. Dicharry also advocates the style of strength training that MacKenzie does:
Weight training (at high intensity) requires the runner to produce forces well above those seen during running. It's possible to activate a very high percentage of a runner's muscle mass, with minimal physiologic fatigue...it's a great training tool to better develop the runner.
The study I would be interested in seeing would be a six week (or more) preparation program that went above and beyond walking and hopping and prepared new runners with movement drills and basic functional strength training moves. Then compare them to a control group and a nine-week training program.
But even then, that's just going to offer another ray of information for the discussion. The one study that I know of that looked at a pool of very good runners over a long time has been conducted by Jack Daniels, Ph.D., the longtime coach, researcher and author of The Daniels Running Formula. In a phone interview about a year and a half ago, Daniels described to me how he's kept tabs on the elite runners he first studied circa 1970. During the call, he told me how he had completed a third survey with his cohort, and said there was one conclusion he could draw in regards to those who still were enjoying their running and running well. "They were the ones who, over the decades, have missed the most days of running," he said. The ones who had run the least were the least broken, in other words.
More: The Benefits of Slow Running
That's just another piece of the puzzle, of course, when it comes to the discussion of running mileage. Steve Magness, author of The Science of Running, examines the subject of volume in his book and concludes that we just don't know enough—it's his contention that there just aren't enough studies on the subject that one can use research alone to make a decision on what mileage level is the best mileage level.
One of my favorite people to talk to on the subject is Dr. Brian Hickey, a PhD at Florida A&M. In his 40s, Hickey has been a running and track geek since he was a kid, and he's applied his vast knowledge of exercise science toward his own athletic career. Even though he's been competing since high school and ran at Syracuse, he still loves to spend his summers finding duathlons and Masters track meets to frequent. I seem to recall him telling me that he not only likes to enter just myriad race distances, from the 400 to the 5000, but also likes to enter the triple jump. That the guy has been at it for more than two decades and is still racing a lot is one thing; it's another thing to be able to do a field event that I can barely watch because of the impact stress involved.
Hickey, in fact, was a like a third author on the book, Unbreakable Runner, and I'm looking forward to reporting more about what he has to say. He's all about minimum effective dose when it comes to running miles, using functional strength movements and heavy weights as part of his long-term durability plan. "Lift something heavy every day," he told me, saying that even if it's just a couple minutes of heavy kettlebell swings, you don't want to miss out on stimulating your natural testosterone and HGH production. "Don't leave that on the table."
On the subject of mileage, he helped me frame my answer to 20-something runners intrigued by CrossFit Endurance. If you're in your 20s, should you seek to run the least number of miles in your training and use CFE-like workouts to supplant the easy maintenance runs? I think the answer is very individual, and may have something to do with the quality of your mechanics and any mobility issues you have. A thought sparked in discussions with Hickey is that the day that you end up in your 40s or 50s and can't run another step—that the achilles is fried or the back is out or the knee is a shambles—does that day come all at once? Or is it the inevitable result of all those steps you took doing 60, 80 or 100 miles a week while in your 20s and maybe even your 30s?
More: Are Your Easy Runs Slow Enough?
It's different if you're a professional runner who is out to make a killing and be finished with running by the age of 25. But it's a different thing for the age-grouper sort who wants to run forever.
I totally agree with Fitzgerald that running produces adaptations that lead to stronger connective tissue, bone density and the like—durability, as he puts it. My question—for those who love running and want to be able to run in their later years—is what else can you do besides just more running? What can you do to insure your bet? That's what Unbreakable Runner is about.
More: 3 Tips to Run at the Right Intensity
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