Altitude And Air Resistance

[[old] Galt]

Thanks all.<br /><br />Rjw, whatever the true number is, as long as we are comparing only 1 person against himself, whatever that number is, that person will perform better at sea level than he will at altitude... acclimated or not.<br /><br />I am in pretty good shape compared to most people, although not necessarily most people in Boulder.<br /><br />I do long bike rides... sometimes including up 2 or 3 thousand feet over a fairly short distance. All I can add from a personal experience, is that riding here compared to other places that I have lived like a little trip to h***.

[[old] John Rupp]

PaulH,<br /><br />The o2 at altitude is the same, whether for runners, cyclists, or rowers.<br /><br />Erg and cycling times, being aided by machine, have a longer carryover of top speed than running. Thus rowing and cycling times are much LESS affected by the decreased o2 at altitude than is running.<br /><br />Because of greater speeds, air resistance is more of a factor cycling and rowing on an erg, than it is for running.<br /><br />Likewise the benefits of decreased air resistance accrue more greatly for cycling and rowing on an erg, than for running.

[[old] PaulS]

<!--QuoteBegin-John Rupp+Feb 21 2005, 03:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 21 2005, 03:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Because of greater speeds, air resistance is more of a factor cycling and rowing on an erg, than it is for running. <br /> </td></tr></table><br /><br />That must be some stroke, to be traveling faster up and down the slide than you can run. A handle speed of 3 meters/sec would be very fast on the Erg, that would be a 2:13 400M running speed, which sounds like pretty slow running to me, actually more like a fast walk, 9 minutes/mile, a bit over 6mph.<br /><br />Wouldn't these fast runners be doing over 12mph?

[[old] Porkchop]

<!--QuoteBegin-PaulS+Feb 21 2005, 06:21 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulS @ Feb 21 2005, 06:21 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><br />That must be some stroke, to be traveling faster up and down the slide than you can run.  A handle speed of 3 meters/sec would be very fast on the Erg, that would be a 2:13 400M running speed, which sounds like pretty slow running to me, actually more like a fast walk, 9 minutes/mile, a bit over 6mph.<br /><br />Wouldn't these fast runners be doing over 12mph? <br /> </td></tr></table><br /><br />I'm a little late to this, and can't call on any expertise at all, but I have a question:<br /><br />I think it has been established that altitude will not affect the energy imparted to the flywheel, and that the current point under discussion is whether air resistance to the rower's body reciprocating up and down the rail would be sufficiently different at altitude to make a difference in pace. <br /><br />If it were the case that resistance were materially less at altitude, it seems to me that the difference would have to show up either as a corresponding increase in stroke rate, that is, an increase in the speed of the rower's body moving back and forth on the rail, or as an increase in the energy that the rower can transfer to the flywheel (by virtue of being able to move back on the slide during the leg drive with less air resistance, and a similar energy savings during the recovery). <br /><br />I haven't studied physics for decades, but as I recall, air resistance is an exponential function of speed at any given density. (Perhaps, Physicist would be kind enough to help me out with this.) Has anyone calculated the expected difference in air resistance, say, between sea level and Denver, at that low speed of body movement? Am I wrong to think that it is probably trivial?<br /><br />Porkchop

[[old] NavigationHazard]

I've just had a dystopian vision of the future at altitude:<br /><br />Ergers with body hair shaved to cut down on drag yanking away while wearing Tour de France-style aerodynamic helmets that lower air resistance. Sitting on Model Es that feature wedge-shaped composite-fiber seats with fairings to dampen turbulence. Sweeping the rowing world -- the new 75-degree layback, which is maintained during most of the recovery so as to reduce the sail effect of the torso. And everyone chasing the records set by the Nepalese at the Mt. Goodwin-Austin Satellite Regatta of the Crash-Bs....<br /><br />lol:

[[old] John Rupp]

Chop,<br /><br />The decreased air resistance has the greatest effect on the speed and moment of inertia of the fan.

[[old] PaulH]

<!--QuoteBegin-John Rupp+Feb 21 2005, 07:44 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 21 2005, 07:44 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Chop,<br /><br />The decreased air resistance has the greatest effect on the speed and moment of inertia of the fan. <br /> </td></tr></table><br /><br />You may have missed my post, so I'll simplify. Air pressure has nothing to do with moment of inertia. The moment of inertia is a function of the shape of the fan, and its mass. It wouldn't matter if the fan was in Denver, at the top of Everest, or on the Moon. I understand that 'moment of inertia' is a terribly impressive-sounding phrase, but unless you know what it means it's probably best not to use it.<br /><br />The decreased air pressure *does* have an effect on the fan, which is exactly the same effect as lowering the damper setting. So if you want to simulate rowing at altitude try rowing at a lower damper with a marble up one nostril*<br /><br />*(kids, do not try this at home).<br /><br />Cheers, Paul

[[old] John Rupp]

<!--QuoteBegin-Galt+Feb 21 2005, 09:25 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Feb 21 2005, 09:25 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Most relationships in life are monotonic, either increasing or decreasing.  That means that if something gets easier going one way, it will continue to get easier as you go more that way. <br /> </td></tr></table><br />According to Aristotle the highest virtue (skill) is the mean between two extremes, and is always closer to one of the extremes than the other.<br /><br />In the case of altitude the optimal between 0 and 40,000 feet might be 5,000 feet for cycling or rowing on an erg, whereas in the case of running it might be 100 to 300 feet, but not 0 or 40,000, again depending on the activity and the person's capabilities, acclimatization, and fitness.

[[old] John Rupp]

PaulH,<br /><br />I do understand your comments about DF and moment of inertia, that you think they are the same at altitude and in space as at sea level.<br /><br />The cycling world also thought altitude times were slower until Eddy Merckx smashed the hour record at Mexico City in 1972.<br /><br />This was 4 years after the Mexico City Olympics, where many believed in their personal capabilities rather than being afraid of the thinner air.<br /><br />Since that time there is not so much fear about altitude in the cycling and running worlds.<br /><br />I'm of the opinion that since runners can run very well at altitude with --no-- machine mechanical advantage such as cyclists and rowers on ergs have, that erg times should be at least as advantageous and contiguous at altitude as with runners.<br /><br />I have no doubt whatsoever that time will prove this to be true.

[[old] Galt]

Kinda hard to envision a dynamic where decreasing both air resistance and O2 10% might make a person go faster, but decreasing both 20% would make him go slower.<br /><br />

[[old] Porkchop]

<!--QuoteBegin-PaulH+Feb 21 2005, 08:14 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulH @ Feb 21 2005, 08:14 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->The decreased air pressure *does* have an effect on the fan, which is exactly the same effect as lowering the damper setting. <br /> <br /> </td></tr></table><br />So, Paul, I take it then that the effect of altitude on the fan, if any, would be uniquely apparent only at a damper setting of 1, with the lever touching the stop. Does anyone ever row at that setting (at any altitude)?<br /><br />Porkchop

[[old] Sirrowsalot]

<!--QuoteBegin-John Rupp+Feb 21 2005, 06:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 21 2005, 06:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><br />Erg and cycling times, being aided by machine, have a longer carryover of top speed than running.  Thus rowing and cycling times are much LESS affected by the decreased o2 at altitude than is running.<br /><br /> <br /> </td></tr></table><br /><br />You've made this point about "mechanical advantage" more than once, but have not addressed why it is relevant. Why does the fact that I'm on a machine mean I have a "longer carryover" of top speed? When I ride a bike, I can certainly go longer in a minute than when I run, but I've still put in the same amount of effort to do so, where does the "carryover" come into play? And you've continued to ignore the claim that one is travelling slower on an erg or in a boat than when one runs. Please explain the precise relevance of this "mechanical advantage." Are you saying that it's easier to erg for five minutes at maximum intensity than to run? If so, what is the basis of this claim? the fact that when I'm on the erg, I'm on a machine? And why do you always group rowing with cycling? Because both take place on machines? Rowing times, at the elite level, are a good bit slower than running times, while biking times are significantly faster. Clearly the rowing machine, despite it being a "machine" isn't helping to move any faster than I could run, so what's your point?

[[old] John Rupp]

Alot,<br /><br />Carryover of top speed means that closer to top speed can be maintained over distance, cycling or rowing on an erg, not that it's any easier to do this.<br /><br />This is relevant to altitude as this "closer to top speed" can be extended and maintained longer, due to the higher anaerobic capability at altitude.<br /><br />I have stated that this discussion is about rowing on an erg, not rowing in a boat where the medium is water, not air.<br /><br />One might be "traveling" slightly slower on an erg than running, but the fan is moving at a much greater velocity than a runner, thus the air resistance to the fan is much higher than the air resistance for a runner. Also, this air resistance is different at altitude than at sea level.

[[old] rjw]

<!--QuoteBegin-Galt+Feb 21 2005, 10:13 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Feb 21 2005, 10:13 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Thanks all.<br /><br />Rjw, whatever the true number is, as long as we are comparing only 1 person against himself, whatever that number is, that person will perform better at sea level than he will at altitude... acclimated or not.<br /> <br /> </td></tr></table><br /><br />Galt - I agree with you. Easier to look at when only one variable (elevation) is changed.<br /><br />The challenge is that Mr. Rupp goes "trolling" every now and then and it was my turn to take the bait. All in good fun and we know that he is pulling our leg because it would be scary if he believed most of the stuff he writes.<br /><br />Raoul

[[old] John Rupp]

Raoul,<br /><br />Oh yes I certainly do believe the things that I write. The difference is that I correctly believe them, while you incorrectly don't understand them.<br /><br />This is nothing new. Innovative ideas are often ridiculed and then later accepted by the same ones incapable of understanding their initial significance.<br /><br />Columbus was attacked for saying the world was round, when the majority thought it was flat.<br /><br />World Record holder Jim Ryun was afraid to run the 800 meters at altitude, then Kip Keino took him to the cleaners in the 1500 meters and smashed the Olympic record in the process.<br /><br />Four years later Eddy Merckx smashed the cycling hour record at the altitude of Mexico City.<br /><br />Relatedly to Columbus, Keino, and Merckx, Herb Elliott wrote about his own endeavors: "When one reaches the top the true men who admire greatness are with one... but the rest call one evil in petty jealously."<br /><br />So it goes with ideas. Not everything is tried and tested. It is to the brave souls who believe, strive and explore, regardless of the pettiness of those who whine and complain from the sidelines.