"These sudden joys have sudden endings. They burn up in victory like fire and gunpowder. . . . Too fast is as bad as too slow."
--"Romeo and Juliet," Act 2, Scene 6 (William Shakespeare, ca. 1597), in modern English.
My loving wife often warns me about what she calls "hobby-horses." She knows I tend to be fixated to the verge of obsession on certain topics. When I served as RRCA state rep for North Florida, headphone use was my "hobby horse." I've had other "hobby horses," too, but the headphone thing was most-notable.
I've talked a lot about treadmill running with people who hate treadmills. Some of them are folks who say TMs are no good for training, others don't like the boredom factor. Since late November, I've done every weekday run, including speed workouts, on a treadmill. True, the TM can be breathtakingly boring, but they let me control many training variables. I can adjust one variable at a time and see how my body reacts, or I can end the workout the instant my tendons are in distress.
The initial 35-minute runs are now 60-minute runs, averaging eight minutes per mile. The good news is I'm near the training volume where I was when I was running six days a week and racing once every three months. But the ache in my back and hips is not so good.
It's not the shoes - the oldest of my three pairs has somewhere between 260-270 miles on them, with the newest pair less than thirty. Could it be the treadmill? The "Gait Guys" wrote an article for Triathlete magazine; they warned readers about how a treadmill can adversely affect a runners' gait.
After reading the research by University of Virginia physical therapist Jeff Dicharry, I called the overwhelming majority of the "Gait Guys" article bupkis. Except for that "downhill" thing.
Like a road or trail surface, the feel and comfort of a treadmill varies by manufacturer, model, and even the machine's installation. Ed W. sees treadmills and elliptical trainers as warm-up, not the workout itself...that means run/tri guys like me are not his gym's typical customers. The treadmills in his cardio area are on solid rubber flooring, and thick rubber matting supports his lobby area TMs. There might be a slight slope in the lobby naturally; all the lobby treadmills seem to have this feeling like one is running slightly downhill.
The "Gait Guys" say the downhill sensation is caused by the "pull" of the belt on the runner's lower extremity, in contrast to the "push" of the lower extremity on the ground surface. They say it affects the gait; Dicharry has proven whatever variations exist (in 40 percent of runners) are so miniscule that to tell the difference it requires equipment which exists in only two sports labs in the country.
So, runners who sense that "downhill" feeling on the TM may benefit from an elevation tweak of 0.5-to-1.0 percent. I've tried both; for me a 0.5-percent adjustment is enough to take away that sensation.
The cause of the hip ache is simple - spin class on the "off" days. The exercise bicycle in the gym cannot be adjusted as readily as a "real" bike, or like a "spinning" bike. Different movement patterns cause musculoskeletal aches and soreness.
Any runner who has ever tried to run a pace that is too slow for their comfort has probably found out too late the error of their ways. I like to tell the tale of running with Suzanne at Honolulu's Ala Moana Park in January 2008; a solid minute-to-two-minutes-per-mile decrease in pace left me hobbling after the third day. A pace that is much slower than a runner's intrinsic efficiency forces major gait adjustment, either in stride length or stride duration. A shorter stride length is not biomechanically injurious; a longer stride duration means a longer period of compression time for the large muscle groups and joints. Drive with your shock absorbers compressed beyond their normal range for an extended period of time is most likely going to shorten their lifespan.
So, perhaps it's possible not only for a runner to go at a pace that is too fast - leading to fatigue, overstriding, a compensated gait pattern, and heel-striking - but also too slow on a treadmill.
How can a runner determine what are good training paces for treadmill runs, without going into a lot of trial and error? There are a couple of really good on-line calculators developed by some of the nations' best running coaches (e.g., McMillan, Daniels) which provide optimal pace ranges for easy runs, recovery jogs, and speed work of varying degrees.
I used my Daniels VDOT training pace for easy/long runs as the starting point for treadmill runs. After a time it appears the easy/long run pace is too slow. So, I will probably start at the "marathon pace," a little closer to 7:30/mile, and adjust downward until I find the least uncomfortable pace which doesn't feel too slow.
That's why the later editions of Running Formula, and McMillan's calculator, have pace ranges, because there will always be a sweet spot at each of the intensities which feel best for the individual runner. While running too fast on the treadmill can injure a runner, too fast is no more injurious than running too slow.