Hi, I'm quite confused at the claim that PaCO2 increases during exercise and therefore VE (and the graphs that accompanied it). From all the literature I have read, it states PaCO2 is relatively steady/constant in sub maximal steady state exercise, and even decreases in 'heavy' exercise above the lactate threshold.
If you could, please provide a time stamp to the part of the video you are talking about. Also, if you have a research citation, please provide the link.
@@VivoPhys around the 11 minute mark. The Control of ventilation during exercise (Bruce, 2017) details this with a graph, or Whippp (1989). Most articles I have found allude to isocapnia and then a decrease after the threshold.
I'm guessing you are talking about the graph with CO2 on the x axis and ventilation on the y axis. I did say CO2 increases with increases in exercise intensity. I could have been clearer in this statement. CO2 production does go up with exercise intensity. However, as was the purpose of the slide. CO2 is a powerful stimulus for ventilation. So almost as soon as CO2 is produced it is sensed and ventilation increases. So it does not build up in the blood. Prior to steady state being reached blood CO2 level may increase slightly but much of it is likely buffered by the bicarbonate system of the blood.
@@VivoPhys I understand CO2 increases with ventilation, in metabolic demand matching. The part I am confused about is arterial partial pressure of co2, as your graph says PaCO2. All I have read states this doesn't deviate much in steady state exercise, in order to maintain homeostasis.
@ionabethx6107 the graph is not depicting an exercise session. It is showing what would occur if blood CO2 increased. As in an artificial laboratory research protocol.
I'm glad they are helping. I don't have a recommendation for that specifically. Both Larry Kenney and Scott Powers have good exercise physiology textbooks worth checking out though.
I very much enjoy your lectures, they have been very beneficial during my first year of DPT school. Do you have any study/quiz questions that go along with your lectures? I am in a hybrid program, with not a lot of learning/recall work. I would be greatly appreciative if you have any learning tools that helping with recall or resources to help in this area. Thank you
The best suggestion I can make is to purchase a book on the topic to help with studying. My extra material is just available to my university students. Sorry.
I'm glad to hear that these videos have been helpful. Below are a few playlists of mine I recommend checking out. Exercise Assessment and Prescription Teaching ua-cam.com/play/PLf85BhZ0yM_tp3V3nTQzOprhzW-hn7QSd.html Exercise Physiology Teaching ua-cam.com/play/PLf85BhZ0yM_s4yE3nmNQQLC0fH6mvQ931.html Exercise and Fitness Calculations ua-cam.com/play/PLf85BhZ0yM_uO0w5u9XL6KxWGqQJ9Kd6p.html
@vivo-phys Evan matthews I really can't get why oxygen partial pressure is decreasing in elite athletes because as compared to untrained person elite have less increase in heart rate that means there will be more time for saturation at lungs right??so why it is still decreasing in elite and becoming hypoxic???
There is minimal difference between heart rates at maximal exercise, but stroke volume is much greater in the elite athletes. This translates into faster blood transit in the lungs and less opportunity to saturate the blood with oxygen.
Great lecture again. minor detail:: you keep mentioning lactate acid but we have hydrogens and lactate but not lactate acid i learned from your other lessons.
Unfortunately, this was a misconception in my knowledge until recently. Some of my older videos likely talk about lactic acid as a single source rather than lactate and acid produced separately but simultaneously. The practical implications remain largely the same, but the mechanistic details change. I have been slowly redoing videos to correct this issue. Thanks for pointing out that this video needs put on the list of videos to be redone.
Check the description below. I list one from Larry Kenny and one from Bill Powers. They are probably the most common undergrad exercise physiology textbooks.
Great video, really helping me to better understand my cardiorespiratory physiology module. Thanks for your work!
I'm glad it helped.
Hi, I'm quite confused at the claim that PaCO2 increases during exercise and therefore VE (and the graphs that accompanied it). From all the literature I have read, it states PaCO2 is relatively steady/constant in sub maximal steady state exercise, and even decreases in 'heavy' exercise above the lactate threshold.
If you could, please provide a time stamp to the part of the video you are talking about. Also, if you have a research citation, please provide the link.
@@VivoPhys around the 11 minute mark. The Control of ventilation during exercise (Bruce, 2017) details this with a graph, or Whippp (1989). Most articles I have found allude to isocapnia and then a decrease after the threshold.
I'm guessing you are talking about the graph with CO2 on the x axis and ventilation on the y axis. I did say CO2 increases with increases in exercise intensity. I could have been clearer in this statement. CO2 production does go up with exercise intensity. However, as was the purpose of the slide. CO2 is a powerful stimulus for ventilation. So almost as soon as CO2 is produced it is sensed and ventilation increases. So it does not build up in the blood. Prior to steady state being reached blood CO2 level may increase slightly but much of it is likely buffered by the bicarbonate system of the blood.
@@VivoPhys I understand CO2 increases with ventilation, in metabolic demand matching. The part I am confused about is arterial partial pressure of co2, as your graph says PaCO2. All I have read states this doesn't deviate much in steady state exercise, in order to maintain homeostasis.
@ionabethx6107 the graph is not depicting an exercise session. It is showing what would occur if blood CO2 increased. As in an artificial laboratory research protocol.
Any resources you suggest to better understand the implications of VE vs VC02 slope in normal individuals? Thanks! Your videos are very helpful
I'm glad they are helping. I don't have a recommendation for that specifically. Both Larry Kenney and Scott Powers have good exercise physiology textbooks worth checking out though.
I very much enjoy your lectures, they have been very beneficial during my first year of DPT school. Do you have any study/quiz questions that go along with your lectures? I am in a hybrid program, with not a lot of learning/recall work. I would be greatly appreciative if you have any learning tools that helping with recall or resources to help in this area.
Thank you
The best suggestion I can make is to purchase a book on the topic to help with studying. My extra material is just available to my university students. Sorry.
I am enthusiastic about exercise physiology but unfortunately I don't have the money to pay for the classes.Thank you very much for your lessons.
I'm glad to hear that these videos have been helpful. Below are a few playlists of mine I recommend checking out.
Exercise Assessment and Prescription Teaching
ua-cam.com/play/PLf85BhZ0yM_tp3V3nTQzOprhzW-hn7QSd.html
Exercise Physiology Teaching
ua-cam.com/play/PLf85BhZ0yM_s4yE3nmNQQLC0fH6mvQ931.html
Exercise and Fitness Calculations
ua-cam.com/play/PLf85BhZ0yM_uO0w5u9XL6KxWGqQJ9Kd6p.html
Thank you.
These videos were very helpful thank you
Thank you for the feedback.
Hi Dr Evan Matthews, I love you, you're so much better than my prof (hopefully he doesn't see this)
Thank you. Sometimes it just takes hearing the same material from different perspectives to finally understand it.
@vivo-phys Evan matthews I really can't get why oxygen partial pressure is decreasing in elite athletes because as compared to untrained person elite have less increase in heart rate that means there will be more time for saturation at lungs right??so why it is still decreasing in elite and becoming hypoxic???
There is minimal difference between heart rates at maximal exercise, but stroke volume is much greater in the elite athletes. This translates into faster blood transit in the lungs and less opportunity to saturate the blood with oxygen.
Great lecture again. minor detail:: you keep mentioning lactate acid but we have hydrogens and lactate but not lactate acid i learned from your other lessons.
Unfortunately, this was a misconception in my knowledge until recently. Some of my older videos likely talk about lactic acid as a single source rather than lactate and acid produced separately but simultaneously. The practical implications remain largely the same, but the mechanistic details change. I have been slowly redoing videos to correct this issue. Thanks for pointing out that this video needs put on the list of videos to be redone.
Hi, thanks for the informative session. Can you suggest some good exercise physiology textbooks that you have come across. Thanks in advance.
Check the description below. I list one from Larry Kenny and one from Bill Powers. They are probably the most common undergrad exercise physiology textbooks.
@Gabriel Reichert Blume The ACSM has an advanced exercise physiology textbook that is worth checking out.
I am teaching remotely but using synchronous lectures. So I won't be uploading any lecture videos. Sorry.