Why is physiological difference between running 25 mpw and running 60 mpw?

Tldr

But, oxygen, efficiency in form, recovery is improved until point if diminishing returns, 60 miles is probably well within most runners limits

bump

kenyahigheweeeeefefa wrote:

1.IF a runner is a well-developed by running 25mpw years ago, he has already untapped the potential to improve by vo2max and running economy. Can he improve by upping to 60 mpw?

2. IF a runner is logging 60 mpw to reach his potentail, suddenly in the next year he drops back to run 25 mpw. How much 5k time will he have or no difference at all?IF so, why the eilte runners are still running 100 mpw?

Is the only difference the weight of runners which make them become faster due to greater weight loss following the greater volume of training schemes?OR there will any improvement in running economy and vo2max?

I'll bite.

A runner's vo2 max will improve if they go from 25 mpw to 60 mpw.

A runner will lose fitness (vo2 max will eventually decrease) dropping from 60 to 25 mpw.

Weight affects vo2 max (BMI is a part of the formula for vo2 max). However, weight is not the only factor and a particular individual's cardiovacular fitness is also a factor. Go to any big road race and you will see 200 pound guys running faster than skinny guys. Of course if that 200 pound guy got down to 160, he would be lot faster.