Originally Posted by
Jordan Feigenbaum
Can you define what cardiac output is and how it is different in absolute terms from ProTour rider to a Continental level rider
Once again Ripp likes to delete my posts, despite the fact there is nothing particularly contentious with them. But since a well-respected SS coach on this board is asking me specific questions, let's see if he will let this one go through.
This is not a difficult concept to grasp. VO2 is defined as per the Fick equation:
VO2 = Cardiac Output x (a-v O2 difference)
Cardiac Output is also defined as Heart rate multiplied by stroke volume. so the equation can then be defined as:
VO2 = Heart Rate x stroke volume x (a-v O2 difference)
This is basic textbook information, and I don't think that I am telling you anything that you don't already know. But those are the variables that affect aerobic performance. Stroke volume (and by definition cardiac output) by far has the greatest ability for improvement. Training has little to no affect on maximal heart rate, and although training may impact the (a-v O2 difference), it does not nearly have the same degree of plasticity as stroke volume.
Yes, there are other variables that will determine performance as well such as cycling economy and and lactate threshold. If this is where you are going with your argument, yes strength training does impact both of these factors. Regardless, the adaptation that best predicts aerobic performance is cardiac volume (which lead to an increase in stroke volume => cardiac output). If you have data specifically on the differences (or lack thereof) of the cardiac dimensions between ProTour and Continental level riders I would be happy to see it. It is entirely possible that cycling economy and differences in the lactate threshold become more important in elite level riders. It is also important to point out that I am not discounting the importance of strength training as it will help to improve aerobic performance. However, increasing someone's cardiac output (which does not happen to any significant degree through strength training) will have a far greater impact on improving performance than would the doubling of their squat.
It seems that you as well as the other SS coaches on here don't believe that cardiac output is primary limiting factor on aerobic performance. If so, then you are a bit outside of the mainstream and that is fine. I welcome you to challenge the argument. I know that there are dissenting opinions by other researchers such as Tim Noakes that I am not going to go into because I don't think this is where you are arguing from. However, The onus is then on you to present your case because the preponderance of evidence would not seem to support what you are saying. But then again, it is difficult to see what you are saying because so far all you and all of the other SS coaches on here have provided to dispute what I have said is a "nuh-uh".