Every so often when I’m in a reflective mood, I think about all the ways I’ve chosen to spend my time over the years, and wonder if those choices have led me to overlook activities that might have given me great pleasure, had I only allowed them into my life.

Home brewing. Never done it. Have I been missing out?

Yoga. Rock climbing. Playing jazz trumpet. Contract bridge. Ballroom dancing. Never done those things, either. Maybe if I had, today I’d be a supple, strong-shouldered, jazzy, card-dealing, fox-trotting fiend. But I never tried, so I’ll probably never know.

One thing I’ll never regret is the time I’ve spent fox-trotting about the roads and trails and tracks of the world. If anything, I find myself wishing I’d spent more time running and less time doing what I’m doing right now, which is typing. But in the last few days, I’ve wondered whether I’ve shunned an activity that might have been satisfying in its own way. I’m talking about running on treadmills.

For most of my life, the word to describe my feelings about treadmills would be “disdain.” It has been a long prejudice of mine that running on a treadmill must be inferior to running on the solid surfaces of the planet. I don’t really know where this prejudice comes from, because I don’t really mind seeing other people using treadmills.

For years I’ve done a regular six-mile run from my house that, in its final mile, takes me past a health club with its steamy glass windows framing the efforts of dozens of people on treadmills, stair-masters, and other aerobic exercise equipment. On cold winter nights, I always feel an odd connection to those folks, even though I’m outside freezing my butt off, and they’re inside sweating their butts off. Anyway, I feel no animus towards the indoor set for choosing treadmills over the questionable charms of Washington St.

Furthermore, I don’t seem to harbor similar prejudices about, for instance, listening to music through headphones rather than listening to it live, or watching a movie on TV rather than seeing a play in a theater. One’s not inferior to the other; they’re just different.

And maybe even not so different. A recent article by Amby Burfoot in Runner’s World points to a blog post by bio-mechanics expert Casey Kerrigan, who claims that most of what we think we know about how treadmills are different is wrong. According to her research, running on a treadmill is pretty much the same as running overland. Even one real difference — the lack of air resistance when running in place — is a factor only when you’re running quite fast, say faster than 7-minute miles.

I have to admit, I have assumed without solid evidence that running in place on a treadmill was not the same as covering actual distance, that it used muscles differently, that setting the machine at an incline was a poor substitute for running up a hill. It looks like I was wrong.

Running in the snow and slush Wednesday, I started wondering what it would be like, how my life would be different if I owned a treadmill and could do runs in the family room while listening to podcasts or watching House of Cards. Maybe I’ve been missing out all these years.

Still struck by this thought, the next day I returned later to Kerrigan’s blog post, perhaps looking for inspiration to join that local health club. But reading her post again, this time something else struck me:

Towards the end of her post, she writes (emphasis mine):

I don’t like keeping constant track of how far or how many minutes I’ve gone while I’m actually running so I either keep my eyes off the reading on the console, throw my towel over it, or change the reading so that some other parameter is front and center. Of course I do check now and again as the last thing I want to do is run a hundredth of a mile more than I set out to run.

That was it. Suddenly all my old prejudice came back but with twice the intensity. Once again, I began to see treadmills as part of a worldview that sees running as an effective, but not particularly pleasant form of exercise, to be endured for the prescribed time but not one second longer. I swore at myself for being almost taken in.

Then I made a mental note not to clear space in the family room, pulled on four layers of winter clothing, and headed out into the February snow.