Guest guest Posted November 16, 2004 Report Share Posted November 16, 2004 Hi Peggy, I'm not sure what practical use a machine like this to the athlete, however , my main comment would be that anaerobic threshold is not a good predictor of VO2 Max. An elite distance runner will have an anaerobic threshold of approximately 80--85% of VO2 Max, whilst an untrained individual might be down around 50--60%. In other words, anaerobic threshold will change with appropriate training. It is of more use to ascertain the velocity at which VO2 Max and anaerobic threshold is achieved. I suggest that you locate some of the work by Veronique Billet on how to use practical methods to establish those parameters and how to use them in a training programme. Pedrick, Adelaide, South Australia. --- Peggy Bowes wrote: > > > Greetings, > > I have a question regarding ventilatory threshold: > I am considering purchasing a VO2 measuring machine > that measures ventilatory threshold in order to > caluclate VO2max. The premise used is that > ventilatory threshold approximates anaerobic > threshold. > > Is this a valid assumption? > > The equation used is the ACSM- equation, which > I can't seem to find anywhere. > > Is anyone familiar with the ACSM- equation? > Can anyone direct me to studies, websites, > textbooks, etc. that would help me learn more? > > The person selling the machine claims that the > results are accurate within 4% of a gas-calibrated > VO2 measuring device. He is also marketing a device > with an oxygen sensor which is accurate to 1-2% of a > gas-calibrated testing device, but it is much more > expensive. > > Is 4% " close enough " for the average person? > > Any advice/help would be greatly appreciated! > > Regards, > Peggy Bowes > Mesa, AZ > > [Non-text portions of this message have been > removed] > > > > > > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted November 21, 2004 Report Share Posted November 21, 2004 Thanks for your insight, . However, the equations for the machine do NOT assume that anaerobic threshold equals VO2 max but that ventilatory threshold equals anaerobic threshold which is used to *predict* VO2 max. The VO2max number is not critical to the program, but rather the heart rate associated with ventilatory threshold, which is used as the basis for a cardio program based on heart rate. I'd like to know if equating ventilatory threshold with anaerobic threshold is a valid assumption. Regards, Peggy Bowes Mesa, AZ Re: Ventilatory threshold Hi Peggy, I'm not sure what practical use a machine like this to the athlete, however , my main comment would be that anaerobic threshold is not a good predictor of VO2 Max. An elite distance runner will have an anaerobic threshold of approximately 80--85% of VO2 Max, whilst an untrained individual might be down around 50--60%. In other words, anaerobic threshold will change with appropriate training. It is of more use to ascertain the velocity at which VO2 Max and anaerobic threshold is achieved. I suggest that you locate some of the work by Veronique Billet on how to use practical methods to establish those parameters and how to use them in a training programme. Pedrick, Adelaide, South Australia. --- Peggy Bowes wrote: > > > Greetings, > > I have a question regarding ventilatory threshold: > I am considering purchasing a VO2 measuring machine > that measures ventilatory threshold in order to > caluclate VO2max. The premise used is that > ventilatory threshold approximates anaerobic > threshold. > > Is this a valid assumption? > > The equation used is the ACSM- equation, which > I can't seem to find anywhere. > > Is anyone familiar with the ACSM- equation? > Can anyone direct me to studies, websites, > textbooks, etc. that would help me learn more? > > The person selling the machine claims that the > results are accurate within 4% of a gas-calibrated > VO2 measuring device. He is also marketing a device > with an oxygen sensor which is accurate to 1-2% of a > gas-calibrated testing device, but it is much more > expensive. > > Is 4% " close enough " for the average person? > > Any advice/help would be greatly appreciated! > > Regards, > Peggy Bowes > Mesa, AZ Quote Link to comment Share on other sites More sharing options...
Guest guest Posted November 25, 2004 Report Share Posted November 25, 2004 With regards to the question: does ventilatory threshold approximate anaerobic threshold? I would suggest that you check out: “Exercise Physiology “ McArdle Katch and Katch 4th edition Chapter 14 “Dynamics of Pulmonary Ventilation” - specifically pg 254- great chart showing the relationship between Ventilatory Threshold and Lactate Threshold as well as OBLA (Onset of Blood Lactate Accumulation) Many authors have abandoned the term Anaerobic Threshold in favor of lactate threshold and Obla (these are two different conditions). With regards to AT (lactate threshold or OBLA) and VO2 max it is important to realize that, depending on many different factors including the fitness level of the subject , AT may occur in some (untrained individuals) as low as 55% of VO2 max or in others (elite endurance athletes) as high as 90% of VO2 max. Another Variable for AT is the activity which an individual is undertaking. For instance and individual’s AT while running is not the same as their AT while cycling or swimming. As an example Lance Armstrong’s AT is in the vicinity of 90% of his VO2 max while riding a bicycle. If you were to test for his AT while running it would probably be closer to 75% of VOmax. For more information on VO2 max go to: (http://home.hia.no/~stephens/vo2max.htm) It is also important to realize that both AT and VO2 max will change independently with increased aerobic fitness and weight loss. For more info go to: (http://home.hia.no/~stephens/exphys.htm) An alternative and inexpensive method of estimating the heart rate at which AT occurs would be the Conconi test. All that is required for this test is a reliable heart rate monitor, a treadmill or bicycle ergometer (with graded resistance) a stop watch and some graphing paper. The test takes about 15 minutes. for details on the test go to: http://www.brianmac.demon.co.uk/coni.htm Unfortunately I no longer have the original article by Dr. Conconi, perhaps someone else on the list can furnish that information. I am not sure why you would need an oxygen sensor unless you are dealing with individuals with severe lung disease. I cannot think of a single situation in which a “healthy” individual would have less thant 98% Oxygen saturation while exercising. (except perhaps if he/she is training at high altitude). If you purchase one of Polar’s heart rate monitors (in my opinion the most reliable on the market) they have several models which will also calculate an individuals VO2 max. (look for models that measure “Own Index”- Polars name for VO2max) Ralph Giarnella MD Southington Ct USA " Peggy Bowes " wrote:: Greetings, I have a question regarding ventilatory threshold: I am considering purchasing a VO2 measuring machine that measures ventilatory threshold in order to caluclate VO2max. The premise used is that ventilatory threshold approximates anaerobic threshold. Is this a valid assumption? The equation used is the ACSM- equation, which I can't seem to find anywhere. Is anyone familiar with the ACSM- equation? Can anyone direct me to studies, websites, textbooks, etc. that would help me learn more? The person selling the machine claims that the results are accurate within 4% of a gas-calibrated VO2 measuring device. He is also marketing a device with an oxygen sensor which is accurate to 1-2% of a gas-calibrated testing device, but it is much more expensive. Is 4% " close enough " for the average person? Any advice/help would be greatly appreciated! Regards, Peggy Bowes Mesa, AZ " Peggy Bowes " wrote:: ....... The VO2max number is not critical to the program, but rather the heart rate associated with ventilatory threshold, which is used as the basis for a cardio program based on heart rate. I'd like to know if equating ventilatory threshold with anaerobic threshold is a valid assumption Quote Link to comment Share on other sites More sharing options...
Guest guest Posted November 26, 2004 Report Share Posted November 26, 2004 Peggy Bowes wrote: > > > Greetings, > > I have a question regarding ventilatory threshold: > I am considering purchasing a VO2 measuring machine > that measures ventilatory threshold in order to > caluclate VO2max. The premise used is that > ventilatory threshold approximates anaerobic > threshold. > > Is this a valid assumption? > Hi Peggy, You mention that this machine measures VL in order to calculate VO2 Max. As I pointed out in my previous post, both VL and AT are highly variable depending on the level of aerobic fitness and therefore are poor predictors of VO2 Max. AT can be also be affected by diet (low glycogen levels following training and inadequate replenishment). Ingestion of caffeine has been shown to influence VT but not AT (Costill et al 1978). VT may be similar to AT, but not necessarily so, there may be a 10 to 15% difference depending on the testing protocol used. Arthur Weltman " The Blood Lactate Response to Exercise " Human Kinetics gives an excellent overview of the relevent research in this area. I suspect that most runners are very good at exercising at VT, or slightly below, simply by monitoring their breathing frequency. Equally many athletes don't use a heart-rate watch as the results are subject to many external variations which render the HR readings unreliable, e.g. cardiac drift during extended endurance sessions. Pedrick, Adelaide, South Australia. Quote Link to comment Share on other sites More sharing options...
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