Treadmill and elliptical, Viva la différence!

I reverted to the elliptical this morning and welcomed the lower impact workout after three days of long runs. While the net benefit of a 22 minute workout may approximately equal that of my usual weekday treadmill run I never feel as though I work as hard on the elliptical. I read an article some months ago that compared the differences between treadmill running and elliptical workouts. Besides the obvious differences in leg motion and the involvement of the arms with the elliptical, the article maintained that the two activities were approximately the same.

If that's the case, why does the elliptical seem so much easier? According to research I've done, while the two workouts burn approximately the same amount of calories per hour (assuming treadmill speed and elliptical resistance are equalized) the lower impact on the user's joints with the elliptical creates a perception that the user is doing less work. That makes sense to me. What also contributes to the difference is that the treadmill sometimes seems a barely tamed beast. At speed, the user must maintain a precise pace and correct position on the tread or risk a serious accident. The noise from a treadmill can also be very loud and that can contribute to tension and perceived effort. The percussive motion of running can cause vibration, so much so that my clock often turns or even falls off the night table when I turn up the speed.

On the other hand the elliptical is whisper quiet (except for mine that occasionally makes a clacking sound when it becomes unbalanced at certain speeds) and this allows the user to watch television or listen to music at a normal level. You can even close you eyes and drift into an alpha state as you operate the machine. Try that on a treadmill. I also find that on longer sessions I can spread the pain a little by making minute adjustments between the efforts I put to the leg part versus the arm part as I maintain a certain rate. It's much more civilized.

At the end, even as I completed my workout this morning drenched with sweat, I still felt that I was missing something. Perhaps it's that running is more aerobic and just plain harder to do. I love that I have a choice between the two machines. The treadmill will always be the preferred challenge and the elliptical will always be a great compromise in terms of doing a workout or taking a rest day.