Apropos of my last post, today's NY Times has an article about the cold weather driving athletes indoors to train on treadmills and bike trainers. In sum, the article concludes they are a substitute, but not a perfect one. Training under real conditions is better. It repeats the old saw that running on a treadmill is easier because of a lack of wind resistance. I have read a lot about treadmill training, and is not so clear. (An excellent summary of the effect of the wind resistance on oxygen consumption and the lack of meaningful difference in oxygen consumption between outdoor running and treadmills is here.)
After an injury several years ago, I researched alot about treadmill running when I was mystified why I ran significantly faster outdoors than I did on a treadmill. First, I discovered my treadmill had an incline. Ok, that was easy. But I still ran faster, further and at a lower heart rate outdoors than on my gym's treadmill. How could that be possible? Particularly given the oft-repeated mantra that treadmill running is easier because of a lack of wind resistance.
In sum, what I found is that unless you run really fast (sub 5:20/mile), the effect from lack of wind resistance from forward motion is negligible. In the Times article, note that the doctor quoted on this issue says that the lack of wind resistance, coupled with a headwind, produces a significant difference. That headwind of course makes a huge difference. And also, if there is a headwind, presumably the course one runs is some kind of a loop, and thus, there will be a tailwind for an equal amount of time, and the net "wind effect" should be zero.
When I was injured, my physical therapists and doctors also advised against setting the treadmill at a steady incline. In sum, that steady incline produces an awkward landing position for the foot that is repeated over many strides. Outdoors, the foot almost never lands in the same position repeatedly even when running on an incline. So the advice was, if I ran at an incline on the treadmill, make sure to mix it up.
And another difference I have read about (but can't find a link for anymore) is that running on a treadmill also eliminates the natural forward body momentum from running. Thus, when running on a treadmill, the weight of the body is supported by the body itself and the body's relative forward momentum is less. In other words, your body is supporting its weight and gets no benefit from the forward momentum generated by running outdoors. The effect of this "lack of momentum" differs for each runner based on speed, gait and running style. For me, because of my, umm, height (and maybe weight) this momentum loss was huge.
The Times article cites to a study that indicates runners run 11.5% faster on a treadmill. That surprised me. After googling some, I am guessing this is the cited study (the abstract anyway). Done at the Royal Veterinary College, on an equine treadmill and measured acceleration and deceleration. I am no scientist, but this doesn't seem to really be on point.
One thing I completely agree with the Times article is that running outdoors works more muscles in subtler ways. Every time I go run outside after a lengthy treadmill season I notice how sore my ankles, calves and shins are. I notice it most in my ankles. That comes from the ankle stabilizing the foot for the subtle differences in landing position for each stride -- something not present on a treadmill.
In any event, I was inspired by the many commenter's dedication to outdoor running even in the depths of winter. And because last week I quoted Thomas Paine, that dedication to soldiering on in winter, not just summer reminded me of his most famous quote:
"These are the times that try men's souls. The summer soldier and the sunshine patriot will, in this crisis, shrink from the service of their country; but he that stands by it now, deserves the love and thanks of man and woman."Admittedly, I don't think Paine was addressing people who ran on treadmills in the winter, but I wanted to tip my hat to those of you who ran outdoors and not just as a "summer runner."