What is implied but not said definitively is that the delta pO2 is as a result of a more dense capillary bed in muscle tissue. Given the results at max power I really don’t understand the trained group having a higher RHR and lower stroke volume unless the amount of training is not sufficient to result in stroke volume increases and the first change is actually capillary bed volume. Does any of this make sense? Interesting article!
To be honest Scott, there were a few findings here that didn’t “make sense” to me totally! I do think that perhaps chronic training might be one explanation here, but we weren’t given that data, unfortunately.
Great summary. What got me: runners' hearts pumped less blood but extracted more oxygen. Efficiency over raw output. This Changes how I think about VO2 max.
Thanks for this fascinating summary, Brady! I’m 70 yrs old and your article is very timely for me personally, because I recently learned that I have 70% blockages in three main coronary arteries, a stupefyingly high CAC score, yet routinely complete marathons in under 4 hrs and have a (Garmin “measured”) vO2 max of 48. I just completed my second Boston Marathon where I qualified for my third with over 20 minutes to spare. I apparently have a genetic peculiarity that causes my lipoprotein A level to be above the 99th percentile, a key factor in my advanced atherosclerosis.
My cardiologist advised me to stop running, which I refuse to do based on my belief that maintaining high fitness in the peripheral system will lessen the burden on my heart. Your article reinforces that belief. To reduce risk, I’ve slowed my workouts to manage my heart rate, but lengthened them, while also mixing in more bicycling, swimming and hiking. So far, so good: no symptoms (yet) and a successful stress test with echocardiogram last week! Thanks again and keep up the great work!
What does this tell us about where the bottleneck is in a fairly fit athlete? If the cardiac output isn't maxed out that suggests peripheral is the limited, yes?
Also, this study compared groups at their max, it would also be interesting to compare them at similar outputs below max.
This (and other data) imply that for elite athletes, the bottleneck may in fact be limited by CO. Because extraction is so high/efficient, delivery becomes the limiter.
Recreational fit at 70bpm? The participant pool is really too small and not well defined to draw any real conclusions. On the other hand recreational fit with bpm in the 40-50 range? Now let's see the difference.
What is implied but not said definitively is that the delta pO2 is as a result of a more dense capillary bed in muscle tissue. Given the results at max power I really don’t understand the trained group having a higher RHR and lower stroke volume unless the amount of training is not sufficient to result in stroke volume increases and the first change is actually capillary bed volume. Does any of this make sense? Interesting article!
To be honest Scott, there were a few findings here that didn’t “make sense” to me totally! I do think that perhaps chronic training might be one explanation here, but we weren’t given that data, unfortunately.
Great summary. What got me: runners' hearts pumped less blood but extracted more oxygen. Efficiency over raw output. This Changes how I think about VO2 max.
Thanks for this fascinating summary, Brady! I’m 70 yrs old and your article is very timely for me personally, because I recently learned that I have 70% blockages in three main coronary arteries, a stupefyingly high CAC score, yet routinely complete marathons in under 4 hrs and have a (Garmin “measured”) vO2 max of 48. I just completed my second Boston Marathon where I qualified for my third with over 20 minutes to spare. I apparently have a genetic peculiarity that causes my lipoprotein A level to be above the 99th percentile, a key factor in my advanced atherosclerosis.
My cardiologist advised me to stop running, which I refuse to do based on my belief that maintaining high fitness in the peripheral system will lessen the burden on my heart. Your article reinforces that belief. To reduce risk, I’ve slowed my workouts to manage my heart rate, but lengthened them, while also mixing in more bicycling, swimming and hiking. So far, so good: no symptoms (yet) and a successful stress test with echocardiogram last week! Thanks again and keep up the great work!
Thanks for sharing! Seems like you’re doing all you can to manage an (unfortunate) scenario due to genetics. Making the most of it!
What does this tell us about where the bottleneck is in a fairly fit athlete? If the cardiac output isn't maxed out that suggests peripheral is the limited, yes?
Also, this study compared groups at their max, it would also be interesting to compare them at similar outputs below max.
This (and other data) imply that for elite athletes, the bottleneck may in fact be limited by CO. Because extraction is so high/efficient, delivery becomes the limiter.
Recreational fit at 70bpm? The participant pool is really too small and not well defined to draw any real conclusions. On the other hand recreational fit with bpm in the 40-50 range? Now let's see the difference.