A forumite took issue
with my original post on this subject. The following are my comments to him.
> All of that and in the end you
> My recommendation is to ignore
any advice that says
> that it is necessary to always
use a 1-2% incline
> adjustment to compensate for
the lack of wind
> resistance. Instead, use the
combination of speed
> control and incline adjustment
that best makes a
> treadmill run "feel like" it
is giving you the
> training benefit that you desire.
> So then the 1 to 2% guideline
is quite appropriate is
> it not?
Since it is often difficult to interpret
emotion within the written word, I’m unsure if your comment is dripping with sarcasm or intended to be tongue-in-cheek.
:-) With your permission, I will assume that you have a sense of humor and intend the latter. :-)
Seriously. No, I do not think the 1-2%
guideline is "quite appropriate". It is appropriate at times for some runners. But, a blanket 1-2% guideline for everyone
to specifically compensate for the lack of air resistance misleads many runners in many situations and can actually make treadmill
running more difficult than over-ground running. It is a "sound bite" response to questions that people post on these forums
in a serious attempt to understand treadmill running vs. outdoor running. And it is a response that addresses only one of
several factors that should be considered....and it’s one that is relatively minor, to the point of being insignificant
for most runners. I think those who are seeking thoughtful guidance to serious questions deserve more than that.
> If you and arepper take issue
with the study I used
> for having a small sample size
then I assume you take
> that same tact with McMiken
and Daniels sinc this
> study had one FEWER subjects
than the Jones and Doust
> study I used.
I don't "take issue" with the study.
As far as I know, it was conducted carefully and in compliance with good scientific practices. I simply observed that, as
arepper noted, it did have a small sample size comprised of highly trained runners, which may or may not be representative
of a broad spectrum of runners of all levels of ability. And, although I did not know it, I am not at all surprised that the
McMiken and Daniels study utilized about the same sample size. I suspect that all such studies are directed to the high performance
end of the running spectrum and use similarly small sample bases. I doubt if any researcher has the resources, especially
time and money, to spend on large samples of a broader spectrum of runners.
All of the studies we, collectively,
have mentioned arrived at a similar basic conclusion....all other parameters being equal, running at speeds below a certain
threshold and at 0% incline is equivalent to running outdoors and the lack of air resistance is insignificant, whereas above
that threshold an incline adjustment is needed to make the two running conditions equivalent at the same pace. What differed
between the studies was the level of that threshold....5:22, 6:00 or 8:03 min/mile. That is what interested me and I speculated
about it. You clarified one of the potential reasons that I had suggested (sample size) so as to indicate that it probably
isn't a factor. At least not for those two studies, which arrived at significantly different thresholds....6:00 vs. 8:03....although
there still could be other differences between their specific sample bases.
Actually, the extract that you cited
from the McMiken and Daniels' report of their study indicates that the submaximal portion of their study only extended to
a 6:00 pace and they found that "neither VO2 max nor aerobic requirements of running were significantly different in track
and treadmill determinations". So, they didn't really arrive at a "threshold" point. If they had continued submaximal tests
to faster paces, they might have confirmed Davies' conclusion that the threshold is at a pace of 5:22.
In any event, the thresholds demonstrated
by all of the studies occur at speeds which are faster than the typical training paces of most runners, thus indicating that
there is no significant difference between running on a treadmill at 0% incline and outdoors in calm air for most runners.
In my opinion, this indicates that it makes no sense to tell the majority of runners that they should compensate for something
that doesn't really affect them.
> I would also note that these
studies were done almost
> 20 years apart. It is possible the technology
> advanced to make more valid
measurements with less
I seriously doubt that the availability
of more modern equipment and technology makes the recent study more accurate or valid than the earlier ones. The conclusions
of all of these studies reflect relative data, not absolute measurements. Any inaccuracies resulting from equipment and/or
techniques should affect both treadmill and track measurements equally in each study. Such measurement inaccuracies should
cancel and not affect the final conclusions, regardless of the technological era in which the studies were conducted. I suspect
the benefit of newer technology is to make the control and analysis processes easier, not to increase their accuracy. ”....but
then again, what do I know?", since I am not an expert in this area. ;-)
> Treadmill calibration is certainly
an issue, but it
> is a red herring in this case
and only clouds the
> issue in a theoretical discussion.
I agree that treadmill calibration would
cloud the issue in a theoretical discussion concerning the effect of air resistance, per se. That’s why I didn’t
mention it in that part of my post. I only raised the point at the end of the post when pointing out that air resistance pales
in comparison to other factors, such as treadmill calibration, in the broader subject of comparing treadmill and over-ground
running....which is what people come to the forum to seek information. In that context, the air resistance issue is the red
herring because it is irrelevant for most runners.
> If the treadmill
> calibration is off (and the
likelihood is pretty good
> if using a health club treadmill
from my experience)
> then it is all moot as you are
not going to be sure
> that is going on.
Precisely the point! I could not agree
more! A miscalibrated treadmill, which is common, as you said, can make all other factors, such as lack of air resistance,
moot....even for the minority of runners who are fast enough to be noticeably affected by the lack of air resistance.
> Lastly, I would not use the
testing protocol to
> support your notion in that
the incline on the
> treadmill is done at the end
of the test for a few
> possible reasons one of which
is safety. In Dave's
> LEAP lab, when the treadmill
is going at sub 5 min
> pace at it would be at the end
of a VO2max test the
> potential for someone losing
balance is pretty high
> (actually had a to catch a kid
on a treadmill one
> time when he stumbled running
at 4:30 ish pace). In
> these cases, increasing the
grade is a means to
> safely increase the intensity
to "max out".
I think I understand your point. It’s
a good one. Perhaps safety is one reason Martin and Coe reduced the pace from 5:00 to 6:00 min/mile for the last few minutes
of their test protocol when they cranked up the incline to max out a runner’s VO2.
The bottom line to all of this is that
I think that, regardless of what the studies indicate, focusing on compensating for lack of air resistance is taking a component
(micro) view of a subject that really begs for a system (macro) view. And it isn’t even one of the more significant
components. Even worse, depending on the other components, introducing an automatic adjustment for it can often actually produce
inequality between treadmill and over-ground running.