Altitude And Air Resistance

[old] PaulH · Post by **[old] PaulH** » February 23rd, 2005, 8:22 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Feb 23 2005, 07:11 PM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(kjgress @ Feb 23 2005, 03:57 PM)</div></td></tr><tr><td class='quote'>my husband lives one week in Denver and one week on Long Island and he is a masters swimmer who trains in both places. He will attest to lower performance here. No, he is not an elite swimmer, but I don't think that matters. </td></tr></table> Swimming is in water, yes? So that is not the same as reduced air pressure on an ergometer fan or a bicycle. </td></tr></table> True, but reduced air pressure on an ergometer fan *IS* the same as lowering the damper. So where is the advantage of being at altitude? Cheers, Paul

[old] John Rupp · Post by **[old] John Rupp** » February 23rd, 2005, 8:49 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(PaulH @ Feb 23 2005, 04:22 PM)</div></td></tr><tr><td class='quote'>True, but reduced air pressure on an ergometer fan *IS* the same as lowering the damper. So where is the advantage of being at altitude? </td></tr></table> That's amazing. So I can just move the lever and, all of a sudden, be at 7,000 feet, for example? If that were possible it would sure save in airline tickets and convenience. Good way to prove they are not the same thing though. Thanks.

[old] Galt · Post by **[old] Galt** » February 23rd, 2005, 8:55 pm

I get 99.98% normal gravity, but even if I am right I don't think it changes the point much... lol.

[old] NavigationHazard · Post by **[old] NavigationHazard** » February 23rd, 2005, 8:58 pm

Or to put it another way, reduced air pressure in the housing means reduced air resistance means the erg flywheel spins easier but takes longer to decelerate. The same effect is produced by lowering the damper setting. Now the P2 and P3 monitors work not by simple measurement of the speed of the flywheel (as did the crude speedometer of the Model A erg) but by factoring in a resistance value derived from tracking the flywheel's rate of deceleration. The Monitor on the Model Bs calculated resistance by averaging it over 16 strokes. Monitors supplied with Model Cs and Ds calculate it instantaneously. Thus, to quote the <a href='http://www-atm.physics.ox.ac.uk/rowing/ ... meter.html' target='_blank'>Physics Of Ergometers web site,</a> "By measuring the damping, the ergometer will automatically compensate for any of the following: * Opening/Closing the vents to increase/reduce resistance * Changes in friction on the flywheel bearings with time * Changes in air pressure, density, viscosity etc. * Environmental factors such as proximity to walls or other ergs" Or if that's not illustrative enough, to quote <a href='http://www.concept2.com/update/S2002/drag.htm' target='_blank'>Concept 2</a> in detail (some posters in this thread already have alluded to it): "Drag factor is a numerical value for the rate at which the flywheel is decelerating. This number changes with the volume of air that passes through the flywheel housing. Since higher damper settings allow more air into the flywheel housing, the flywheel decelerates more quickly, resulting in a higher drag factor value. The electronic Performance Monitor measures the drag factor on the recovery phase of each stroke and uses it to calculate your score. This method of "self-calibration" compensates for local conditions and damper settings, making scores on different Indoor Rowers comparable. Indoor racing and the Online Community are made possible by this method of self-calibration..... "There are a number of conditions that can affect the drag factor: ... "*Elevation/Barometric Pressure- Air at higher elevations is less dense, so, an Indoor Rower that is moved from Boston to Denver will have a lower drag factor range [my emphasis] in Denver.... "Luckily, the monitor compensates ... by using the appropriate drag factor in calculating your score." Yes the lower air pressure in Denver affects the erg flywheel. But the monitor compensates for this. Finally, a big reason that C2 equalizes scores pulled at altitude is because the Crash Bs, BIRCs, etc. are done at or near sea level. Were it not for the compensation, oxygen-deprived people from places like Denver would be at a disadvantage in attempting to meet the qualifying standards for sponsored trips. They might well kick butt when they get there, but first they have to get there.

[old] Porkchop · Post by **[old] Porkchop** » February 23rd, 2005, 9:10 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Feb 23 2005, 07:11 PM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(kjgress @ Feb 23 2005, 03:57 PM)</div></td></tr><tr><td class='quote'>my husband lives one week in Denver and one week on Long Island and he is a masters swimmer who trains in both places. He will attest to lower performance here. No, he is not an elite swimmer, but I don't think that matters. </td></tr></table> Swimming is in water, yes? So that is not the same as reduced air pressure on an ergometer fan or a bicycle. </td></tr></table> That was the point, John. In my question to you, I asked (paraphrasing here) whether there were any studies of athletes in events that would not involve reduced air pressure. I suggested swimming as one. The idea here is to test your hypothesis regarding performance at altitude by athletes with a high degree of aerobic conditioning in a circumstance where O2 levels are the only factor that should affect performance. Your theory involves two variables, air resistance (as affected by altitude) and O2 concentration. A study of swimmers would isolate one of the two factors that we have been discussing, O2 concentration, precisely because air resistance is a trivial factor at best in swimming performance. Porkchop

[old] John Rupp · Post by **[old] John Rupp** » February 23rd, 2005, 10:01 pm

Nav, Yes the DF is different at altitude. I already said this earlier. However, different air flow is not the same effect as the different air density at altitude. "Finally, a big reason that C2 equalizes scores pulled at altitude is because the Crash Bs, BIRCs, etc. are done at or near sea level. Were it not for the compensation, oxygen-deprived people from places like Denver would be at a disadvantage in attempting to meet the qualifying standards for sponsored trips." If c2 is saying that changing the DF reduces the oxygen, then that surely is not the case.

[old] John Rupp · Post by **[old] John Rupp** » February 23rd, 2005, 10:05 pm

Chop, I'm satisfied with the results of runners as with regard to differences in o2 availability and consumption and likewise with cyclists. Considering the variables of aerobic fitness, this would be no different with rowers or swimmers. The exception with cyclists and ergometers is that the machines have the capacity to extend the range of the athlete's aerobic components, again depending on their fitness.

[old] PaulS · Post by **[old] PaulS** » February 23rd, 2005, 10:27 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Feb 23 2005, 06:05 PM)</div></td></tr><tr><td class='quote'>Chop, I'm satisfied with the results of runners as with regard to differences in o2 availability and consumption and likewise with cyclists. Considering the variables of aerobic fitness, this would be no different with rowers or swimmers. The exception with cyclists and ergometers is that the machines have the capacity to extend the range of the athlete's aerobic components, again depending on their fitness. </td></tr></table> Let's put it this way John. If you put a cyclist on a cycle Ergometer they would have lower power production at higher altitudes than at sea level. You are mixing the problem of actual power output (Ergometers) with Power requirements to attain a speed along a roadway (bicycling), and trying to make the results cross over. Of course this was pointed out in the first post I made in response to your start of this thread. Remember, lwts produce less power than hwts, but they also need less power to move their boats across the water, so there is very little difference in on water performance between lwts and hwts. however on the Erg, the differences are clear. You can still come back to reality and admit you are just being silly... or not.

[old] NavigationHazard · Post by **[old] NavigationHazard** » February 23rd, 2005, 10:30 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE</div></td></tr><tr><td class='quote'>What is c2 saying here, that changing the DF reduces the oxygen? </td></tr></table> If you check the quotation marks in my last post, you'll see that C2 is not saying anything. >I< am characterizing their position, which (fundamentally) is that people who are forced to row qualifying times at lower available 02 levels are at a disadvantage compared to people rowing at full 02 levels.

[old] Porkchop · Post by **[old] Porkchop** » February 23rd, 2005, 10:39 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Feb 23 2005, 09:05 PM)</div></td></tr><tr><td class='quote'>Chop, I'm satisfied with the results of runners as with regard to differences in o2 availability and consumption and likewise with cyclists. Considering the variables of aerobic fitness, this would be no different with rowers or swimmers. The exception with cyclists and ergometers is that the machines have the capacity to extend the range of the athlete's aerobic components, again depending on their fitness. </td></tr></table> I thought we had already established that some portion of the performance variation for cyclists (and to a smaller degree, runners) was related to diminished air resistance. The question is "how much?" The only way one could establish that is if one isolated the O2 component in a population of elite(?) aerobic athletes. (Or, perhaps, to strap oxygen tanks on cyclists so they could inhale sea-level O2 concentrations at altitude.) 2. I don't understand your last two sentences. What variables of aerobic fitness are you referring to? What would be no different with rowers or swimmers? How do bicycles and ergometers extend the range of the athlete's components? (I don't think I really understand what that means, anyway. What do you mean by the athlete's "components," and what does it mean to "extend" their "range"?) Porkchop

[old] Andreas · Post by **[old] Andreas** » February 23rd, 2005, 11:09 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(TomR/the elder @ Feb 23 2005, 06:54 PM)</div></td></tr><tr><td class='quote'>This unraveling thread demonstrates some truth about human behavior, but it has nothing to do w/ fitness and altitude. It appears to be that if someone makes a ridiculous assertion and sticks to it, all sorts of people will work determinedly to shake him (or her) from that position, despite all the evidence that reason has no place in the discussion. I can't help but wonder if John cares about anything other than the attention he gets. John's views are like impossibly gaudy lures that despite violating the laws of nature manage to cause the fish to bite. And to bite. And to bite. Imagine if people actually did use the ignore button. Lonely John would troll in the dark water fruitlessly for his daily catch. Tom </td></tr></table> AMEN Andreas

[old] starboardrigged1seat · Post by **[old] starboardrigged1seat** » February 23rd, 2005, 11:21 pm

I'm not really sure I have anything to contribute to this conversation....but wow. John, it looks like you've thoroughly embarrassed yourseslf. The number 1 limiting factor (size of the rower excluded) over a 2,000m race on the erg is the individual's fitness. This means a number of things, including how efficiently your muscles utilize the oxygen, power-per-stroke, anaerobic threshold, and maximal oxygen uptake. Since there is less available oxygen at altitude, your body will have to work harder to maintain a similar wattage at the same stroke rate (a higher heart rate for same amount of work) than at sea-level. There is no possible way that putting an athlete in a situation where he will perform better on a test that basically measures maximal oxygen intake at altitude with less oxygen than he would at sea level. It would be the same has having a cyclist (Eddy, who you seem so eager to quote) to perform a VO2 max test on a stationary cycle at the altitude of Mexico City, and then again at sea level and see what he performs best at. By the way, your shot at Matthew Pinset is completely uncalled for. He's a much more accomplished rower. Just think -- your PATTs put you around 90% for your age group. That means that you're competitive for your age and weight. His 4 OLYMPIC GOLD MEDALS say that he's the best in the world. Consider that next time before you take a $hit on anyone else's accomplishments.

[old] John Rupp · Post by **[old] John Rupp** » February 23rd, 2005, 11:24 pm

Chop, I would say the performance variation for 10k runners is virtually all due to the physiological components, and not much with reduce air resistance except sprinters. So in this case we already have the separation of the air resistance from physiology, determining physiological effects to be 20-30 seconds for a 10k in fit athletes, thus coming to 3-4 seconds for a 2k event. These same physiological components apply also to swimmers, cyclists, and rowers, with the exception of the machines extending the range of the beneficial anaerobic components. As example, Eddy Merckx did the first kilometer of his hour record in approximaely 60.6 seconds. I don't have the exact time but this is close, which was fast enough to place in the medals for the 1000 meter Olympic time trial event!!!!! Then he continued on for the hour. Can you imagine a 10000 meter runner beginning with a 48 second 400m and the continuing on to run 13 miles in the hour???? Unbelieveable and this would be totally not possible. However on the bicycle it was possible because of the advantage of MACHINE as aid to the performance of athlete. This is the same case with the rowers on ergometers. You can have a big heavy guy with a fast sprint then this same person will do well for the half marathon event, whereas with running this person would be stopped by the 800 meters and no more. There are not the same limitations with ergometers and bicycles as with runners, where the performance depends entirely on physiology, not machine.

[old] Sirrowsalot · Post by **[old] Sirrowsalot** » February 23rd, 2005, 11:32 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(starboardrigged1seat @ Feb 23 2005, 10:21 PM)</div></td></tr><tr><td class='quote'> By the way, your shot at Matthew Pinset is completely uncalled for. He's a much more accomplished rower. Just think -- your PATTs put you around 90% for your age group. That means that you're competitive for your age and weight. His 4 OLYMPIC GOLD MEDALS say that he's the best in the world. Consider that next time before you take a $hit on anyone else's accomplishments. </td></tr></table> Agreed completely, the reason age categories exist is for older folks to be able to compete and give them something to strive for when their bodies begin to break down and they quite naturally lose both fitness and strength, not so these older people can then make crazy assertions, like having times close to other fifty year old men is the same as being fit. John, saying you're the fittest or fitter than me for your age means the following: "because my, John Rupp's, feebleness and lack of fitness can be attributed to my age, it can be adjusted away." However, I think that you'll find that when you sit back on the erg, the feebleness is still there. John, you're old in an absolute sense, slow in an absolute sense, and and weak in an absolute sense

[old] John Rupp · Post by **[old] John Rupp** » February 23rd, 2005, 11:32 pm

Nav, Yes I noticed where you said, and c2 said. The thing is that c2 says you adjust for the DF with the damper and make the DF the same and then this takes care of all the effects etc etc etc from the altitude and then everything is the same as at sea level. Then they say hey wait a minute it is NOT all the same!!! So we have to give some advantage to those poor folks and subtract some time to give them a trip to come see us!!! Nevermind that someone somewhere else went faster!!! So it's really a gift you see. On the one hand it's supposedly all accounted for, but then not really so there has to be some "adjustment"? Well you can't have it both ways. There either IS a difference from the altitude irrespective of the DF, or there isn't. I say there is a difference, and c2 agrees with me (after saying there isn't). They agree and they don't agree.

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