Posted by Frank Day (63.201.228.13) on January 17, 2004 at 19:46:10:
In Reply to: Some more discusiion and questions posted by Juerg on January 17, 2004 at 18:13:32:
: So I like to get some more answers from our readers.
: Point 1 : Altitude : We had somewhere a statement , that breathing more ( faster ) in altitude does not get more oxygen in the blood.
: Why do we increase the breathing in altitude.?
: If we move in altitude we may produce something like an acute oxygen deficit, because of an acute drop of the PO2.
: Could it be, that as a compensation of this lower PO2 we may increase first the respiratory volume and than also the numbers of breath ( faster breathing ) or respiratory minute volume ?.
: Could it be that the chemo rezeptors in the carotissinus and the aorta may stimmulate the breathing center to increase the above values to try to bring more oxygen into the blood ?
: When I worked in the altitude trainig center in Switzerland we did some very simple exercises to show some coaches what may happend in altitude.
: One is : measuring the PO2. First you force the athlete to keep the number of breath/minute on the number he uses on sea level. Than you let him breath they way he is feeling comfortable.
: And you see , they breath faster.
: You also see in the first part ( slow ) breathing an additional drop of PO2 even below the already lower PO 2 in altitude.
: So perhaps the faster breathing may help to increase the oxygen content in one or the other way in the blood ?
: Is this adaptation the same for anybody.
Yes, the adaption is the same for everybody.
Actually breathing at altitude will get more oxygen to the blood but it is a marginal amount. It is only at very high altitudes where oxygen in the blood falls significantly that the low oxygen drive for breathing will begin to have an effect. Usually breaathing is CO2 driven. However, by blowing off CO2, we do make more room for oxygen on the hemoglobin molecule. It just is not effective in enhancing performance but might keep you alive on the top of Mount Everest.
: From what we see no. There are people they seem to have less increase of number of breath /minute.
: To test this we did some very simple studies.
: 1 group did nothing over 3 month , just returning home on about sea level. The other group did a very specifc respiratory training for their inspiration muscle system.
: 3 month later we check the numbers of breath / min in both groups.
: Group A was the some as the first time , group B had a clear lower increase of breath per min than 3 month before in altitude.
: Why ?
We can have also conscious change in breathing pattern. What mentioned are patterns that exist in everyone. Conscious changes in breathing patterns cannot be sustained and except perhaps for hyperventilation before swimming or sprinting events are not of much use for athletic performance.
: 2.Different position in different sports like cycling , downhill skiing , rowing and so on can as discussed , produce some mechanical strain on your upper body.
: Therefor it may be possible that the restriction in expansion for the rib cages and the inspiration muscles may get harder. a ) the position is so tight ( equipment ) , that there is no expansion for the thorax possible. If the athlete tries to breath harder , he may actually produce something like an isometric contraction for his inspiration muscle, and or if he can still expand , he may need some much more force ( and also energy ) Could it be that this now used energy for breathing may be missed in other parts of the body ? If the breathing muscle system would be stronger and in better " shape " could this perhaps help to " offer " more blood for other muscle in the body ? Under very heavy intensity up to 20 - 30 % of the total energy expenditure may be used just for the breathing system.So one of the questions may be , whether this system could be in certain cases the limiting factor for perfomance ( together with others.)Perhaps it may be possible to strengthen the breathing muscles as well as we strenghten other muscles in the body ?
: So some positioning in some sports may make it perhaps harder to breath the full vital capacity.
This is better attended to by improving the positioning of the athlete than trying to improve the capacity of the muscles to overcome poor positining. We are not talking about wrestling here but cycling where the positioning of the body can be controlled by the athlete.
: As we discussed , this restriction may be because of position or and because of some obstruction in the airways ( Turbulanzes )Even hard but exercised induced asthma ( as one possible reason ) may be more common in endurance athletes as some may think. ( Cross country skiing , biking and so on. )
: If the external breathing system out side air to the alveoly is not important or a limiting factor for performance than we can stop at least in our athletes to take " spray s " like ventolin " or others if they have exercised induced asthma. In fact the whole testing and banning from broncho dilatation type of medication or broncho spasmolytica is waist of money and time. The question remains , whether this restriction may reduce the overall performance in a negative way.
Any restriction that prevents full respiratory function can adversly affect aerobic performance. However, Upper airway restriction (other than asthma) usually is not of any concern. In anesthesia is is possible to keep patients alive without any chest wall motion. This is called high frequency ventilation where the frequency is so high (100's) and the volumes so low (much lower than the dead space) that it enhances diffusion. This form of ventilation allows the chest surgeon to work in a "quiet" field.
: Measuring something with the name Tiffenau test ( how much air do you get out in the first sec. from you Vitalcapacity can perhaps be used to see , whether the reduced performance may be caused by : Position and therefor restriction of the expansion of your breathing system , or perhaps whether it is a more obstuction problem of air flow.
forced expiratory rate cannot usually be changed by any means as higher intrathoracic pressure causes two things that mitigate against increasing flow rate. It compresses the airways reducing the available cross sectional area, making flow harder and, once turbulent flow is achieved, higher pressure makes almost no difference in flow rate regardless of driving pressure.
: Once we saw , that different positions for example on a bike , may reduce the vitalcapacity and therefor perhaps may be one ( besides others ) of performance restriction, we checked different neck resp . head positions.
: How.? You stay in the same position as before. First you check your Vitalcapacity in upright position and the Tiffenau.
: Than you go in your racing position and you do the same. . Than you move just your neck and test Tiffenau again.
: If the % is dropping than we may have to ask the question , whether this new position may be caused by not as optimal airflow in intense work outs.
: Our numbers show a change.
: As long we can see a clear difference in athletes feelings and actual measurement we may go with this , and not with the commong theory.
: Which sometimes may be also wrong , so we have to change and reasses again.
It may be possible that one can measure a change when someone is put in the racing position on the bike and that changing this position improves the breathing dynamics. However, the same change will also change the aerodynamics. Most of this probably has to do with diaphragmatic restriction rather than airway changes but I may be wrong. However, all of this stuff is interconnected and one cannot look at just one thing and ignore everything else.
: Last but not least there is still the question why in certain sports we actually try to hyperventilate or why after a 400 m the athletes are breathing very hard.( even using their help inspiration and expiration muscles.
: There is the metabolic elimination of Lactic acid ( and Lactate )where an easy jogging arround would be helpful as well and the buffering. Could it be that the forced breathing ( body may try to get rid of some of the acidosis with this reaction - successful or not is another question )expiration ( Get ride of CO 2 may help to reduce the acidosis. ?
One must look at how the body transports O2 and CO2 to understand this difference. O2 is not water soluble and CO2 is. Therefore, no significant oxygen gets to any cell unless it is carried on hemoglobin (even if one is in 100% oxygen environment - it is laughable watching the football players suck on the oxygen mask on the sideline - it is all psychological). The easiest way to increase oxygen to the cell is to increase the hemoglobin. So, if you want to improve oxygen delivery, get an altitude tent, live at altitude, or become a doper. Because of the way hemoglobin works it hardly matters how much oxygen is in the lungs (within reason) as to how much gets put on the hemoglobin. Further, an acid environment forces more O2 off the hemoglobin when it is near the cell, so Lactic acid helps in this end. CO2 is water soluble, so CO2 is stored in the entire body, not just in the red blood cells. So, we can sustain quite a bit of anaerobic metabolism with substantial CO2 build up without having a big change in the partial pressure or pH. Once the pH starts to change substantially then cell function starts to decrease and we have to stop exercising (at least hard). However, at this time, there is substantial CO2 built up and we will continue to breathe hard after we stop exercising until this extra stored CO2 is exhaled and pH and PCO2 is returned to normal. It is rather "simple" physiology.
Perhaps there some things lost in translation Juerg so if I misunderstood your questions (or you misunderstand my comments) please ask again.
Frank