Donovan Rebbechi said:In article said:I'd go by time and perceived effort on the treadmill. I think I've seen studies that say to
increase the slope by about 2% to make it equivalent effort to road.
My understanding is that this only takes into account the energy cost of drag.
And frequently that's all people are concerned about.
Quoted message said:
Quoted message said:FWIW, I'm setting the treadmill during circuit training (1 min work session, but well into 2-hr,
mostly hard training session) about 2 mph faster than my easy running speed (6mph treadmill with
0% slope vs 4mph or slower, sometimes much slower with steeper hills, for "easy" effort on hilly
trails) in order to get any benefit from it. Later in the winter (maybe tomorrow?), we'll increase
the slopes (last one is set at 15%) of of the treadmills to get more benefit from them.
Do you think this has more to do with your usualy training surface (soft trails with lots of
hills) or something else ? I find it's pretty similar (I do about the same pace on treadmill and
other surfaces), but I usually run on pavement, road or track, which makes the treadmill the
slowest training surface I use.
Dunno.
Knee jerk response 1: Calibration errors. I have absolutely no idea how accurate the treadmills are.
My own measurements of distance are probably conservative so that my real pace is probably
underestimated (faster than what my numbers show). One of the reasons I posted the numbers was to
give a sense of the degree of difference that can exist - both in terms of calibration and the
effect that footing has. With respect to trail running, this fall was the first time I ran similar
routes enough times under similar weather conditions to even get a grasp on "average" pace. I always
run by perceived effort. Things that affect pace: wind, temperature, mud and its quality (not all
muds are created equal, as Doug will attest to), snow / ice (and their quality), falling snow, rain,
dark, eyes staring back at you in dark, etc. - and not just a few sec/mi, more like a couple
min/mile in deep snow or shoe-sucking mud. That's without considering hills. My easy flat trail in
town may have differences of a couple min/mile, depending on conditions. What I'm saying in a round
about way is that "pace" is a concept that really only has meaning under very limited conditions -
like flat roads in good weather.
Knee jerk response 2: Flat treadmill running is *really* easy compared with hilly trails. We leave
treadmills running at 5mph, hop on, adjust for whatever we want, then back to 5mph for next person.
I found 5mph on flat treadmill, which is my "race" pace for 3-4 mi trail race, to feel like I was
slacking. (The 3mi was the first leg of duathlon so I was probably holding back, and the 4mi race
probably only had a few hundred feet of hills, if that. I still think both of them are a little on
the short side since there's no way I approach 12min/mi on my normal routes.)
I usually use the flat treadmill as a place to catch my breath in the circuit, so it was really
weird to find myself reaching up and cranking up the speed to get a reasonable effort. They wanted
the treadmills left at 0% for now. Once they start cranking up the slope on those things (not sure
if that's on agenda for tomorrow am or not), up to 5% will probably still feel easy, about 10% is
where I notice it, and 15% I'm slowing down. This is why I look for hills >10% to be meaningful as
hills. But a 15% (nominal) treadmill slope does not approach anything except my gentlest hills (what
I'm calling 5-10%) for feeling. I can usually still have my heel land after my forefoot on a 15%
treadmill, but most of my real hills I need to do forefoot only as I don't have the achilles
flexibility to do that, and I'm not sure it's appropriate technique (one of the reasons I watched
the elites at WMRT and played/replayed DVD). This is why I try to do many of my drills on a ramp
rather than flat.
Knee jerk response 3: Footing on treadmill is so much easier than trail that the same conditioning
will result in faster pace. That is, footing (not so much softness) limits speed on trails. (might
be a corollary to KJR 2)
Alternative hypothesis 1: The change from the hill work (including a little steep single track) I
did from Mar to Aug made "flat" seem really easy. But I'm running mostly flat (relatively speaking)
trails right now. So I'd tend to reject this hypothesis.
Alternative hypothesis 2: One of the biomechanical issues my PT identified last year was
hypermobility in metatarsal region (or something like that) whereby my toes fail to act as lever. I
can see this slowing me down more on trails than on treadmill since the belt just keeps moving and I
pretty much just pick up my feet in appropriate cadence. If this is true, then at least for people
like me, treadmill running is definitely not the same as running on a motionless surface. This is
one reason I spend so much time on foot exercises and dorsiflexion.
Alt hyp 3: I run faster after 1.5 hr hard work 😉 Yea, right. Reject that one too. However, I do
notice that my achilles cooperates more in warm-hot weather, which I only get mid-summer or on
treadmill.
Another thought. My first couple times on the treadmill this fall, my gait was horribly bouncy and I
was having a tendency to run almost up on the front deck. I sped the treadmill up to a point where I
could use my normal stride and cadence. That was about 6mph, but felt I could go faster.
Also, since we've only met a few times so far this fall, I may not have the cumulative tiredness
that comes after several hard weeks like that (1-wk recovery isn't quite enough for total recovery,
esp. if I do some of the drills mid-week), but not sure that it would affect my trail running.
Keep in mind that speedwork to me might be some fartleks if footing permits so for me to crank up
the speed means something is really lacking.
YMMV, obviously.
Dot
--
"Success is different things to different people" -Bernd Heinrich in Racing the Antelope