Spikes had a nice lengthy chat with Shannon about her standout 2016 campaign.
http://spikes.iaaf.org/post/a-year-of-contrasts-for-shannon-rowbury
“Alberto really values having a full indoor season. I seem to be responding well to that system,†she says. “I feel that I’m benefiting now from this two peaks cycle. And it’s just challenging me and stimulating me, and I think it seems to be helping me in improving each little mini-season.â€
That quote confirms what I've always thought. When pros don't do indoors or xc, it's not beneficial. Yes, the college season is super long but if you don't do something in the winter, then as a pro you stagnate as you've got nothing to motivate you from August until April.