I like the treadmill.

Before you go all “dreadmill” on me, or remind me of the merits of training in all conditions, let me explain why.

The majority of my running career has taken place in Houston, Texas. First at Rice University, and then for another three years and three marathon builds, I’ve adapted to heat so intense and humidity so thick that one visiting Olympic marathoner equated it to feeling “slapped in the face.” That was an early morning in May. August would have destroyed her.

As important as suffering through tough conditions are to me and my coach Jim, the treadmill still played a role. Major hills, first of all, are hard to come by in Houston, and so I used to hop on a machine once a week or so to run “hills” while Jim worked the dials and studied my form. We’ve also manipulated treadmills to mimic the elevation changes of upcoming marathons. Doing so especially paid off at CIM.

And finally, there were a few days when I had a super long workout or tempo on tap and the heat-humidity combo was brutal, even by Houston standards. The treadmill allowed me to do the work without beating my body up so much that significantly more recovery would be required. It also offered an up-close, every-angle perspective for Jim, who played with the variables depending on my heart rate and handling of the load.

Since moving to Boulder, Colorado two years ago, treadmills have been equally advantageous, but in a different way. For one thing, I’m a thousand miles from Jim, who continues to coach me remotely. Throwing me on “the mill” every so often gives us a concrete checkpoint that Boulder’s trails and roads, with their endless variables that he does not know, just can’t. This is not to say that a treadmill workout is a completely accurate representation of a person’s fitness. I don’t think that it is. (Keep reading.) But it does offer us a common language, and to me, is worth keeping in the rotation for that.

It goes without saying that treadmills are also useful in Colorado when snow and/or ice render normal running surfaces dicey. Some people are able to run confidently and stay on their feet in those conditions. I’m in awe of them! True Texan that I am, I’m exceedingly cautious when my footing’s not sound. I tiptoe through runs like Fred Flinstone behind the wheel, I walk across any wooden bridge that glistens, and if I’m not careful, a few runs with that odd motor pattern will leave me trashed for days. So when I wake up to a winter wonderland, I weigh my location options carefully. Then I choose the one with the most potential to toughen me up, build my fitness, and leave my body in a good state.

My support for treadmills doesn’t mean I think that treadmill and land running are the same. I’ve seen people bang out workouts on a machine that they couldn’t dream of replicating outside. To me, that suggests a poorly calibrated machine, a stride that’s predisposed to benefit from one, or an unhealthy reliance on technology.

I also have friends who just can’t get past the monotony and real-time feedback of treadmills. Those cases remind me that running hard, in one spot, with little external stimuli and all the thoughts in the world, might not make you all-conditions tough. But there’s still a lot to be gained—like focus, rhythm, discipline, and self-awareness—from the human hamster wheel. And if running in place in a bathtub full of pillows was worthwhile to Emil Zatopek, the odd treadmill workout is worthwhile to me.

So my official stance on the treadmill is: Pro, when used occasionally and purposefully and as a complement, not a crutch.

Happy training, friends and hamsters!