What do you consider "fast" running while training?

Since following Matt Fitzgerald's plan for the marathon and utilizing the running portion of his Olympic plan on Training Peaks, I've been following PZI (pace zone index).  

http://home.trainingpeaks.com/blog/article/using-pace-zone-index-(pzi)

It follows the same concept of Jack Daniels' VDOT (used by the McMillan calculator), but it specifies the "gray zones" that you want to stay out of when training.

For me Zone 6 is fast but I can hold it for a while (usually Fitz likes to build to a 2x20' workout using this zone).  Zones 8 I can clarify as fast.  Zone 10 is hard, but it has its place in training.

The link didn't work for me, but I found the page. If you Google Training Peaks Pace Zone Index, it's the first link.

Interesting concept, but I struggle with totally pace-based efforts. Effort level and pace don't always quite match up due to fatigue, weather, etc... 

Though, apparently, they're attempting to address that: "Extreme shifts in temperature or radically different footing will obviously affect your ability to train in paces that correlate correctly with your PZI. Similarly, running up and down hills will result in situations that make it difficult to prescribe proper intensity based on PZI. Training Peaks is actively working on Environmental Shift Factor™ and Altitude Normalized Pace™ algorithms to remedy these situations."

In Tucson, when it's 50 in the morning and 80 in the afternoon, that's a big enough shift to affect pace, for sure.

So, you consider, by those standards, Z6 and above to be "hard"?

Yes.  Z6 is reserved for Tempo efforts and other threshold type workouts.  It's pretty close to what your 10K pace would be.  Z8 is a hair faster than your 5k pace.

I don't see much Z4 used at all in the Olympic tri plan, but in the marathon plan it was used as a "race sim" in your long run to get a better feel of what a marathon at race pace is.  That kind of running doesn't really have a place in short course.

Z2 gets used more for warmup and recovery run efforts.

Z3 is where most of the long run and foundation efforts get done.  The current plan I'm on has me running most of my time in Z2/3 with some running in Z6 and Z8.  This follows the "mostly easy, sometimes hard" mindset that people like to post about.

Stephen Seiler gave an interesting presentation that points to the base of "mostly easy sometimes hard"

http://www.canal-insep.fr/fr/training-periodization-deep-root-cultural-heritage-and-innovative-paradigms-2013/ei_13_10_va_pr_stephen_seiler-mov

The punchline is that across various sports elite athletes spent 80% of their training at "easy efforts" and 20% at "hard efforts".  Another study that was referenced in the presentation found that even for time limited athletes (i.e. people like us) also benefit from a similar approach.  

While reading "Racing Weight" I noticed that Matt Fitzgerald referenced Seiler's research, and I found looking back in my marathon plan (which was written by Fitzgerald) that my approach was very similar to what Seiler recommended in reference to training load.  While I did not reach my goal in the marathon, I did PR in my 10K by over 30s using a far easier training approach than I did the first time I broke 40s.  

Back to back all-out 5k's every 6 weeks? Ouch!

I guess if it works well & keeps you on track, it's all good though

So, you'd consider fast to be anything above Z4 aka "10 percent slower than marathon race pace"?

Simplified - to you, fast in training is training at or below your marathon pace? If you'd run it in a race, it'd be fast in training?

Makes sense to me... but what I don't like about this definition is that my marathon PR (my ONLY marathon) is waaaay slower than it should be

I use the Daniel's VDOT approach using current race times to dictate different training paces.

Training paces are pretty specific for training different "systems" and depends on the purpose of the workout. 

My very loose and personal description of "fast" is anything 30k race pace and faster.  It's basically a pace I can run "sometimes" while still building good volume and not overdoing it.

IOW, I can't run 40-50% of my training miles at 30k race pace or faster.  I can run about 20% of my training miles that way.  I'm sure others are different...and as always...YMMV.

Z4 actually between 10% slower than marathon pace to marathon pace.  Like I said before, when training for tris I spend zero time in this zone. 

For marathon training, Z4 could probably be considered fast, but in tri training I would consider Z6 and above fast.

As for the last point, my marathon PR is slower than it should be in theory as well, but marathons (for me anyway) are really, really hard to train.  My last full was early January, and my pacing was dang near perfect until the infamous mile 20 wall.

The fact that your PR is slower than it could be means that we're both probably missing something, and from what I've read the answer is probably not enough volume.

I 1000000% agree with that statement. 

My only marathon was ~12 weeks after a 70.3. The 70.3 was the "A" race, and I took a rest week, a build week, then did a 10 week plan averaging like 35mpw I think. I could probably dig up the numbers.

I know I could run it a lot faster with a longer focus and more of base going into marathon-specific training.

Using a 48:00 10k...

"Long/Easy" is in PZI Zone 3

"Marathon" is at the fast end of PZI Zone 4

"Threshold" is at the fast end of PZI Zone 6

"Interval" is 0:01 faster than PZI Zone 8

Lots of correlation between the two systems.

That's not a coincidence.  "PZI represents a practical evolution of the principles developed by legendary running coach and author Jack Daniels. "

What PZI does is specifically categorize the paces outside of those zones as zones to be avoided while explaining why in a less technical way than JD does.

Makes sense. Similar to the "less than marathon pace = fast" crowd.

When I first started I was doing HR training, spending most of my time in Z2.

Over the last couple of years I've moved more towards a combination of  RPE and the McMillan calculators.

Most of my volume now is at a "long" pace as per McMillian.

I'll maybe do one tempo run per week, but most of my 'speed' work comes from doing more free-standing 5K's, about one a month or so.  I use a rolling average of my  most recent 5K times to periodically re-calculate my McMillan training times.

Mark

Ah, these are some interesting callouts as well.

I definitely agree with the "mostly easy, sometimes hard." Because the terms fast and slow are totally different than easy and hard. Not to further complicate things...

And it's not just you

Additionally, there is a whole heck of a lot that can go wrong in 26.2 miles so it's very difficult to have a perfect race. Plus, it's not like you can just get back out there and do it again the next weekend like you can some distances. 

Out of the 5x I'm suppose to be running a week.  Typically only once "maybe" twice will I run "fast".  Now for instance this upcoming Saturday of nine miles I will run marathon pace that I want to hold.  Which means about a 7:00- 7:05 pace.  I know that's not "super hard effort for me" but, after 13 or so miles it starts to get a tad taxing..  Was doing speedwork on Tuesdays and Thursdays up until a few weeks ago but I typically will still run under 7 or so for a couple miles on Tuesdays here and there.  Otherwise it's typically zone 2-3.

Found this cool acapella of Radioactive this morninghttp://www.youtube.com/watch?v=kgS33TnYZI0