Originally Posted by
rubiksoval
That's not junk miles. For all the lauding of polarized training, hardly anyone actually does it. And assertions like the above simply aren't accurate in regards to what actual bike riders actually do and how they perform when doing it.
To me this feels like a "no real scotsman". Just because hardly anyone does it does not mean it isn't valid as a training method. On top of that polarized training has been a staple of top level athletes for years. Whether someone chooses to use polarized training if they are not competing athletes is then another topic entirely.
You can overtrain doing too many slow miles, you can overtrain doing too many medium miles, you can overtrain doing too many hard miles. None of that has antyhign to do with whether or nto you can improve at a specific intensity, ESPECIALLY an intensity that drives aerobic performance benefits while also being repeatable multiple times a week.
While it is possible to overtrain doing slow miles, it is incredibly difficult to do so. Especially so if one has all other aspects in life (sleep, nutrition, rest etc) in order.
It is not nearly as difficult to overtrain when doing medium to high intensity stuff as it is really quite taxing to the body. On the other hand paradoxically it isn't really effective in forming the changes in the body that HIIT does. So you don't get the volume but neither do you get the intensity training.
Overtraining when doing HIIT is incredibly easy so one should limit that to one to max two times a week.
But you can combine the volume of the slow miles and the intensity of the HIIT so you get both benefits. You can't do that if you feather the red line all of the rides you do.
And again, the point you missed in my earlier post. This is theoretical. Doing something is always better than doing nothing. More people should do stuff even if it is the dreaded 'junk miles'. But for optimal training polarized training makes the most amount of sense while going at medium to high intensities for a relatively limited amount of time per week does not make nearly as much sense.