Leaving out the why of it, Stephen Seiler's website seems to agree
pretty much with what Ken says I think.

The what of it seems to be easy to summarize : intensity takes precedence
in any week where it occurs, and that should be 'every' week. (Even the
elite take several weeks off just after the competition season.) By
precedence, I mean that if one of intensity or LSD has to be skipped
for some reason, skip the LSD. So in that sense, it seems to agree
with the original premiss of this thread. For elites, the suggestion
is about two intensity sessions every week all year (except those
few weeks off). But lots and lots of LSD is also recommended, and
the level is lower than most of us maybe do.

Getting older, or maybe for any non-elites, maybe not stating the
intensity till July or later, and making it usually once a week
till much closer to snowtime, seems to make sense to me. Whether
the LSD should then be a lot faster is a question which I can't
seem to decide about. That's more fun, but sometimes I get prety
tired it seems. So I blame that on maybe not enough sleep. But
maybe that's caused by trying to do too much at too high a HR.

I haven't actually looked at Seiler's site for a few years, so
correct me if that's out of date. I think a lot of his info is
from Norwegian coaches and physiologists, and from a time that
might indicate that that's pretty much how Ulvang trained. Despite
my profession, I'd take the advice of the doer (Ulvang), not
the theorist.

Best, Peter