^Coach Friel raises some good points, particularly about athletes in their first years of training, although some of the studied athletes were HS juniors who still trained polarized.

My take on the video presentation is that it rather blows the theory of specificity out of the water. Thoughts?

Another rather obvious point is that VT1 and VT2 are quite easy for an experienced athlete to notice in training. Particularly, using the polarized system to train either below VT1 or above VT2 gets rid of the necessity of a HRM and perhaps even a PM, except as aids for recording training. I've been training with a HRM for 15 or so years and it's easy for me to see, going by either VT, when my HR is depressed from previous hard training, being tired, etc. Probably much more accurate to go by the VTs. Thoughts?

Some of the comments on the training studies linked in the blog remark on the distribution of HR in the various zones. Anyone who is doing polarized training has seen that basically HRs above VT1 should be during efforts above VT2: it just takes a while to get there. On a 4 minute interval, as little as 1.5 minutes might be in HR z5. My understanding is that it's the duration of the effort, not the duration of the HR that we are interested in measuring. So that's still the value of a PM since it helps to even out interval power. Of course experience will do that, too. And of course PMs don't help anyone but cyclists while they are cycling. Thoughts?

Edit: It comes to me that polarized training is very simple to implement and to a large degree removes the coach from the training process except for form and training volumes. Thus I would expect to see some resistance from coaching firms.