Are shorter Z2 rides beneficial?

[savechief]

I've been adding 2 shorter (min 45 minutes, max 1 hour) Z2 rides per week during lunch hours in an attempt to increase overall training volume. This is in addition to two interval sessions during the week (currently doing 6x5' with 2' RBI @ 110-112% FTP), a fast group ride on Saturday and a 2 hour ride on Sunday. A typical week might look like this:

Mon: Rest
Tue Evening: Intervals (15 miles)
Wed Lunch: 45' @ Z2 (12 miles)
Thu Evening: Intervals (15 miles)
Fri Lunch: 45' @ Z2 (12 miles)
Sat: 55 mile club ride
Sun: 25 mile ride, mostly Z2/Z3

I thought that I had read somewhere that Z2 rides were not effective unless they were several hours long, which is why I'm asking the question.

[Tapeworm]

Shorter answer is: yes.

Long answer is: yes, depending on a variety of factors. If the z2 is being *added* to your schedule, and this then equates to more volume overall then it should definitely help. If it is replacing a harder session then it comes down to how the rest of the sessions stack up against it in terms of creating the required stress and allowing the required recovery. It also means that the "quality" work needs to be quality.

It is likely that upping the intensity of the z2 session would be more effective...for that session in isolation. When extrapolated to the context of weekly/monthly cycle it might be adding too much stress. Context!

Look up (if you haven't already) some of the stuff going around on "Polarised Training" Stephen Seiiler. I don't use it myself BUT there is some excellent information which pertains to your situation.

[savechief]

Thanks for the answer. I have been doing some reading on polarized training, but I will continue to do more. The two, 45 minute Z2 sessions are not replacing anything, they're only adding to what's already there. The Tue/Thurs interval sessions are definitely very hard, and the Saturday group ride can be very hard at certain points. At this time, I don't want to add a third interval session, but we'll see as I progress.