Altitude And Air Resistance

[[old] John Rupp]

<!--QuoteBegin-starboardrigged1seat+Feb 23 2005, 07:21 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(starboardrigged1seat @ Feb 23 2005, 07:21 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->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.<br /> </td></tr></table><br />But you see that's exactly the issue.<br /><br />You're mixing up vo2 max and PERFORMANCE.<br /><br />The vo2 max doesn't matter -- at -- all.<br /><br />Eddy Merckx broke the 1 hour World Record at Mexico City.<br /><br />That's what counts.

[[old] Sirrowsalot]

<!--QuoteBegin-John Rupp+Feb 23 2005, 10:32 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 23 2005, 10:32 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Nav,<br /><br />Yes I noticed where you said, and c2 said.<br /><br />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.<br /><br />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!!!<br /><br />So it's really a gift you see.<br /><br />On the one hand it's supposedly all accounted for, but then not really so there has to be some "adjustment"?    <br /><br />Well you can't have it both ways.  There either IS a difference from the altitude irrespective of the DF, or there isn't.<br /><br />I say there is a difference, and c2 agrees with me (after saying there isn't).<br /><br />They agree and they don't agree. <br /> </td></tr></table><br /><br />I really hope you're being intentionally stupid, or this is the biggest yet of your many embarrassments. Listen carefully: The drag factor and erg account for the effect of the change in air density on the fly wheel. It does not account for the lack of oxygen in the air that the rower has to breathe. I always find it particularly hilarious when someone (you for instance) hysterically denounces others (C2) for their incompetence, when he (you) is the one who is completely incompetent. You sound like an old fool. Are you?

[[old] rjw]

<!--QuoteBegin-John Rupp+Feb 24 2005, 03:24 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 24 2005, 03:24 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><br />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.  <br /> <br /> </td></tr></table><br /><br />Merckx's first kilometer was done in 1'10" and five kms. in 5'55.7". <br /><br />You pull these numbers and so called facts out of the air. He did set the 10km and 20 km record on the way to his hour record. <br /><br />Of course he had the mechanical advantage of the bicycle - that what he was doing - but he was aerobic machine. It was possible because of his superior fitness not because he was having a picnic on the bycycle.

[[old] ebolton]

Actually, somebody could use the fan laws to calculate how much less power is required to spin an erg flywheel at 5280 ft vs. 0 feet elevation, given the same damper setting. See the relationships under #2 on this page:<br /><br /><a href='http://nrmurphy.com/fans_laws.html' target='_blank'>http://nrmurphy.com/fans_laws.html</a><br /><br />I'm sure it would be an amount that could be corrected for by opening the damper assuming it's not all the way open (#10) at sea level.<br /><br />Merckx chose to go to Mexico city, and not because he wanted a fresh Corona. Here is a simplified explanation of why things go farther at altitude:<br /><br /><a href='http://www.usatoday.com/weather/tg/wbas ... asebal.htm' target='_blank'>http://www.usatoday.com/weather/tg/wbas ... htm</a><br /><br />Merckx also timed his record attempt so he could take lots of time to acclimate. Not easy to do for somebody who raced as much as he did. The lower air resistance would not have been enough if he had not. He knew he was balancing better aerodynamics with less favorable physiological effects, and he made the judgement Mexico would be a better hour if he was acclimated sufficiently. Even now, when cyclists race far less frequently, hour record attempts are at the end of the season and the end of carreers mostly because of the time required to acclimatize.<br /><br />Other people tried to better the record, some at altitude, but Merckx' record stood so long because he was the best- he was the Cannibal. There has been no greater rider, before or since.<br /><br />I think I remembered reading on another thread that Rupp wrapped his flywheel cage with inner tube rubber to quiet his machine down. Perhaps his damper lever doesn't do anything anymore because the exit is totally blocked, and he's forgotten exactly what it does?<br /><br />Ed

[[old] John Rupp]

<!--QuoteBegin-rjw+Feb 23 2005, 08:07 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(rjw @ Feb 23 2005, 08:07 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Merckx's first kilometer was done in 1'10" and five kms. in 5'55.7". <br /> </td></tr></table><br />70 seconds is more in line with his overall pace.<br /><br />If that's the case then I stand corrected on that split.<br /><br />Perhaps it was 70.6 then and a misprint from the article.<br /><br />Do you have an online source for the splits?<br />

[[old] rjw]

<!--QuoteBegin-John Rupp+Feb 24 2005, 04:17 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 24 2005, 04:17 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Do you have an online source for the splits? <br /> </td></tr></table><br /><br />No. This is as good as I have found. Give a good account as well.<br /><br /><a href='http://www.torelli.com/home.html?http:/ ... our.html&1' target='_blank'>http://www.torelli.com/home.html?http:/ ... l&1</a><br />

[[old] John Rupp]

Ed,<br /><br />I did wrap the model B with truck tire inner tube, but not completely. There are gaps inward and outward of the damper ring, and the non fan side is open. The DF's come out the same as for the model C, about 70 to 200 or so.<br /><br />For the model C I have an angled strip of 1/2 inch foam covered by the same truck tire innertube rubber. This comes 1/2 way down from the top of the fan cage in a direct line to the top of my feet. The foam and rubber are held up by a pole, that comes from a 2x4" T-base between the fan cage and my feet.<br /><br />This being in front of the cage, does not cover it and does not materially affect the DF, it's purpose being reduction of noise from the fan and, secondarily, direction of the air flow below me.<br /><br />I do, however, have a piece of plastic taped to the side of the damper opening that does reduce the DF a bit. The minimum setting at the moment is 70 and the maximum is 197.

[[old] Porkchop]

<!--QuoteBegin-John Rupp+Feb 23 2005, 10:24 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 23 2005, 10:24 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Chop,<br /><br />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.<br /><br />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.<br /><br />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.<br /><br />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.  <br /><br />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.<br /><br />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.<br /><br />There are not the same limitations with ergometers and bicycles as with runners, where the performance depends entirely on physiology, not machine. <br /> </td></tr></table><br /><br />John,<br /><br />Sprinters have nothing to do with the issue. Sprinting is primarily an anaerobic activity. O2 availability does not affect performance in sprints; rather it affects post-performance recovery.<br /><br />I still don't understand why you think that the "machine" aids performance at altitude. The machine (erg, bicycle, skateboard) is the same at any altitude. The physiology of the rower or bicyclist determines what he or she can do with the "machine" at any altitude. The ergometer measures work output; it doesn't "aid" the work.<br /><br />Taking it as a given that certain events have been run or cycled at a faster pace at altitude than at sea level, it seems to me that the real question is how much work (a measurable physical factor) it takes to maintain that faster pace. Does the lower O2 concentration limit the total work out put? In other words, if I can theoretically go 10% faster on a bicycle due to lower air resistance, but can't maintain that pace because lower O2 availability reduces my work capacity by, say 5%, then I won't be 10% faster. Faster, perhaps, but still affected negatively by altitude.<br /><br />You seem to be taking the position that at some level of training or aerobic fitness, available O2 levels are irrelevant to performance. That doesn't seem plausible.<br /><br />Porkchop

[[old] starboardrigged1seat]

<!--QuoteBegin-John Rupp+Feb 23 2005, 10:35 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 23 2005, 10:35 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-starboardrigged1seat+Feb 23 2005, 07:21 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(starboardrigged1seat @ Feb 23 2005, 07:21 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->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.<br /> </td></tr></table><br />But you see that's exactly the issue.<br /><br />You're mixing up vo2 max and PERFORMANCE.<br /><br />The vo2 max doesn't matter -- at -- all.<br /><br />Eddy Merckx broke the 1 hour World Record at Mexico City.<br /><br />That's what counts. <br /> </td></tr></table><br /><br />VO2 max matters absolutely on the erg -- it's one of the only things that do matter over 2k. Eddy Merckx broke that record on a racing bike in the open air -- not on a cycling ergometers. Like I said before -- the machine is not the limiting factor, rather individual athletic performance. And VO2 max is the ultimate indicator of that over a 6 minute event. I understand that it's kind of late in this argument for you to back down on your views, but it would better for you to just stop arguing. You're really embarrassing yourself.

[[old] John Rupp]

Chop,<br /><br />Yes I agree that sprinters have nothing to do with the issue.<br /><br />The machine aids performance at any altitude. This aid is greater at altitude due to the thinner and lesser density of the air.<br /><br />I believe the work output will be the similar, regardless of the altitude. vo2 max is a measure of work output, but it's correlation with performance is low. Thus it does not suffice as a single measure or predictor of performance.<br /><br /><!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->You seem to be taking the position that at some level of training or aerobic fitness, available O2 levels are irrelevant to performance.  That doesn't seem plausible.<br /> </td></tr></table><br />Okay, do you think oxygen utilization is the "only" limiting factor to performance?<br /><br />If you do, then only our oxygen utilization capacity will determine how fast we can run.<br /><br />However I believe you will agree there are many other physiological factors that can affect one's performance.

[[old] John Rupp]

If -- and since -- oxygen utilization is not the ONLY factor that limits performance, then reduction of available oxygen by 10% will not result in a 10% reduction in performance.<br /><br />Indeed this is the case. If it is true that oxygen availability is 10% less in Kenya, for example, then 10k times should be at least 3 minutes slower. It would not be possible to run a 10k within 20 seconds of one's sea level time, at altitude.<br /><br />This 20 seconds is only a 1% difference.

[[old] starboardrigged1seat]

<!--QuoteBegin-John Rupp+Feb 24 2005, 12:22 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 24 2005, 12:22 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->... <br /> </td></tr></table><br />?

[[old] Parky]

I resolved some months ago never to get involved in a Rupp Thread, but I can resist no more, as this thread has proved to be the best entertainment since Steffi Graf retired from tennis.<br /><br />Here's my modest contribution...<br /><br />When undertaking athletic events at altitudes above sea level there are two opposing factors at work:<br />1. There is less air resistance. Thus, if you are moving through the air as part of the athletic event, there is a benefit to be derived. The faster one goes, the greater the benefit.<br /><br />2. The concentration of oxygen in the air is lower. As a result, the amount of power that an athlete can produce over a given period of time is reduced. I don't pretend to understand the mechanism by which this occurs, but this assertion is supported by a vast wealth of anecdotal evidence. I don't think it would be too hard to prove the assertion by means of a proper, controlled scientific study.<br /><br />Pretty uncontroversial so far, I hope.<br /><br />For indoor rowing, the first of these factors is largely irrelevant. The C2 monitor automatically compensates for the reduced air pressure. The benefit from reduced air resistance moving up and down the slide is negligible. Thus, for indoor rowing, the only significant impact on performance at altitude is the second factor. For any individual, for any distance, performance at higher altitudes will be worse than at lower altitudes.<br /><br />For sports where the air resistance overcome by the athlete is significant (e.g. running, cycling) there will be a distance at the altitude in question at which performance is the same as at sea level, because of the way the two factors work in opposition. For distances shorter than this, altitude will be a benefit. For longer distances, altitude will be a disadvantage. Thus, in terms of absolute performance, sprinters would prefer to perform at altitude and distance runners at sea level.<br /><br />Also pretty uncontroversial, I hope.<br /><br />Just as two individuals will not react in exactly the same way to changes heat and humidity, so two individuals will not react in the same way to altitude. Mr Bloggs may be naturally relatively better at altitude than Mr Smith. Although Mr Bloggs may be naturally relatively better at altitude than Mr Smith, he will still be absolutely worse at altitude than himself at sea level. Obviously, the same comments apply to Mrs Bloggs, Mrs Smith etc.<br /><br />I have personal experience of this. I went trekking in the Himalayas a few years ago. One of the members of my group was an old, fat bloke, who we all had to wait for at the top of climbs at lower altitudes. The highest climb we did finished at 5600m or thereabouts. This same old, fat bloke got up the climb first, whilst I was gasping like a fish out of water wondering where my lungs had gone several hundred metres below. He was naturally better at altitude than me. (The possibility that he was bluffing on the climbs at low altitude can be ruled out.) Once we got back down to sensible altitudes, normal service was resumed, and he was the one wondering where his lungs had gone.<br /><br />The adverse effects of the second factor above can be partially mitigated by means of acclimatisation, but as Mr Scott says "Ye cannae change the laws of physics" (or indeed biology).<br /><br />DP

[[old] NavigationHazard]

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->If -- and since -- oxygen utilization is not the ONLY factor that limits performance, then reduction of available oxygen by 10% will not result in a 10% reduction in performance.<br /><br />Indeed this is the case. If it is true that oxygen availability is 10% less in Kenya, for example, then 10k times should be at least 3 minutes slower. It would not be possible to run a 10k within 20 seconds of one's sea level time, at altitude.<br /><br />This 20 seconds is only a 1% difference.<br /> </td></tr></table><br /><br /><br />Oxygen utilization is not the only factor that impacts performance at altitude but it is the major factor. Here's why I think you get the effect noted above:<br /><br />A) Just to be clear, oxygen at breathable altitudes is still about 20.9% of the gas mixture we call air. The lower pressure means there is less oxygen available for respiration in absolute rather than percentage terms.<br /><br /> At altitude, or its hypoxic equivalent, the reduction in air pressure means that arterial oxygen saturation tends to drop from its normal 98% or so. This negatively affects fitness, broadly defined as the body's ability to perform work. It is why tourists gasp atop Mt. Evans (14000 ft or so), and why even for Kenyans distance running at altitude is -- ceterus paribus -- slower than at sea level. <br /><br />C) Lowering arterial oxygen saturation triggers adaptive effects. Normally these include: improved diffusability of 02 through the lungs; increased enzyme production in the muscles resulting in greater 02 processing capabilities, one of the consequences being greater buffering effects against lactic acid buildup; and most importantly, increased red blood cell production (typically, but not always, accompanied by a general increase in plasma volume that tends to keep blood viscocity fairly level).<br /><br />D) These adaptive effects vary from individual to individual, both in timing and in intensity. They may start in most individuals after a few hours, but study after study suggests that they really kick in only after prolonged exposure to altitude. I believe this to be particularly true of red blood cell production, which IIRC increases quite gradually, although I can't cite any studies to that effect off the top of my head.<br /><br />E) Over time, the extra oxygen-carrying ability derived from prolonged exposure to altitude and consequentially greater hematocrit levels will tend to compensate for the reduction in available 02. If you take a typical athlete from sea level and move that person to Denver for a sufficient length of time, s/he eventually will recover most -- but not all -- of the performance ability originally lost in that location to altitude effects. Should that athlete return to sea level, his/her performance ability as a rule will be enhanced by the extra oxygen capacity.<br /><br />F) As a general rule the negative effects of moving up to compete are felt immediately. However the relationship between reduced available O2 and reduced event performance is complicated and perhaps non-linear. It depends on many factors including the nature of the activity in question, its duration, the baseline 02-processing capacity of the individual, aerobic vs. anerobic demands, etc. Thus a 20% reduction in alveolar oxygen will not necessarily reduce event performance by 20%. But if you make sufficient demands on someone who is not acclimatized to altitude, they'll end up gasping on the stadium floor as did Ron Clarke.<br /><br />G) As a general rule, athletes who grow up in high-altitude environments and move down to compete do not gain as much fitness as is lost by athletes going the other direction. Why this is I don't know, and I'm not sure anyone does. But I suspect it has something to do with the fact that we are not perfectly efficient processors of oxygen and that the body regards some of its oxygen-carrying ability as superfluous given the newly rich circumstances. At any rate, it is the main reason why (say) Kenyans who can run pretty damn fast 10ks in Nairobi can go somewhat faster at sea level but not orders of magnitude faster.<br /><br />

[[old] PaulH]

<!--QuoteBegin-John Rupp+Feb 23 2005, 07:49 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Feb 23 2005, 07:49 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-PaulH+Feb 23 2005, 04:22 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulH @ Feb 23 2005, 04:22 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->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? <br /> </td></tr></table><br />That's amazing. So I can just move the lever and, all of a sudden, be at 7,000 feet, for example?<br /><br />If that were possible it would sure save in airline tickets and convenience. <br /><br />Good way to prove they are not the same thing though.<br /><br />Thanks. <br /> </td></tr></table><br />No, but your erg wouldn't know the difference, and it's the erg that measures how fast you're going. So for the erg altitude is not a variable, whereas for you it is. Hence you will always go slower at altitude than you could at sea level.<br /><br />Cheers, Paul