Re-looking at running/training effort - Advice.

How did the Polar stuff determine your zones?

Initially, yes.  But I adjusted so my LT is the same as their AT/LT at 180 (for running).  Had to do that by putting in a max HR high enough to move them but it ALSO happened to be what my max HR has been in the past (201).

I can make the mental adjustment.  Polar does it by percentages, but they are close

        Polar              LT

Z1     100-120    120-150

Z2     120-140     150-160

Z3     140-160      160-170

Z4     160-180      170-180    -  Both established 180 as LT

Z5      180-200     180-200

SO, Polar has a lot of Z2 base runs, tempo runs in Z4, and intervals in Z5... (which in terms of "zones" would be similar to BT plans)  HOWEVER, the difference is in the zones themselves.  While Z5 is the same, and Z4 has half an overlap, the bulk of by training would be Z2 which are completely different for the two methods.  If I ran in zone 2 based on LT, I would be zone 3 for Polar.  Zone 2 runs per Polar are LT zone 1 runs.  I know there is a feature to create my own zones, but I think for the preloaded running/cycling modes, they set them automatically.  I would have to look into the documentation.

But is that all bad?  I still wonder if all the high Z2 training I did might have been too hard and a lot more easier running would have made better gains (with all the speed work essentially being the same).

I often hear that people don't train easy enough on easy days and hard enough on hard days.  Maybe I was falling into that same trap with all the high Z2 work?

Maybe I sort of answered my own question...

Looks like Polar's explanation for zone 3 is what the LT method would have you do in zone 2.  Zone 2 (upper zone 1 in LT) is what they say is endurance and using fat as a fuel.  Zone 1 (lower Z1 for LT) is the same - recovery.

Makes sense the LT method would have you doing what polar says is improving aerobic fitness in a training program.  Curious why polar stresses a lot of the "improving basic endurance" and what they call "zone 2" work.

I should look further ahead in their plans and see if they, when closer to the actual event, switch from mostly z2 to z3 work.

I'm just curious if it works or is a valid approach.  Being a pretty big name in fitness over the decades, I'm assuming it can't be complete garbage.

MODERATE	70–80%	10–40 minutes	BENEFITS: improves aerobic fitness FEELS LIKE: light muscular strain, easy breathing, moderate sweating RECOMMENDED FOR: everybody for moderately long exercises
LIGHT	60–70%	40–80 minutes	BENEFITS: improves basic endurance and fat burning FEELS LIKE: comfortable, easy breathing, low muscle load, light sweating RECOMMENDED FOR: everybody for longer and frequently repeated shorter exercises
VERY LIGHT	50–60%	20–40 minutes	BENEFITS: improves overall health and helps recovery FEELS LIKE: very easy for breathing and muscles RECOMMENDED FOR: weight management and active recovery

Training in heart rate zone 1 is done at a very low intensity. The main training principle is that performance improves when recovering after, and not only during training. Accelerate the recovery process with very light intensity training.

Training in heart rate zone 2 is for endurance training, an essential part of any training program. Training sessions in this zone are easy and aerobic. Long-duration training in this light zone results in effective energy expenditure. Progress will require persistence.

Aerobic power is enhanced in heart rate zone 3. The training intensity is higher than in sport zones 1 and 2, but still mainly aerobic. Training in sport zone 3 may, for example, consist of intervals followed by recovery. Training in this zone is especially effective for improving the efficiency of blood circulation in the heart and skeletal muscles.

I have found this to very, very true.  In fact, I have focused a lot of my attention recently in reevaluating what my easy pace should be.  I have been concerned that my easy pace was beginning to creep into the too fast zone.  I believe that too much zone creep on the easy runs contributes to excess cummulative fatigue that hinders quality workouts and puts one at increased risk of injury.  I am still trying to figure out what is best for me but my gut is telling me to slow down the easy pace runs and hit the tempo/interval/repeat stuff harder and with a tad more frequency.

"I often hear that people don't train easy enough on easy days and hard enough on hard days.  Maybe I was falling into that same trap with all the high Z2 work?"

I guess I always felt like a workout should "feel like a workout".  The recent runs I have been doing, although really fun and comfortable, don't feel like I "worked".  Which may not be a bad thing!  Definitely makes it easier to get geared up for an easy run day after day rather knowing It's not going to be a big effort.  I would tend to push high zone 2 if not straddle z2/z3 at the end of the run.  It just feels weird to be running at 135 instead of 155.   It's a world of difference.

I guess I could test it out and see how some races this year are effected. 

Could be a lot of different reasons as to why you plateaued, would need much more info to determine that. With that said, it does sound like you could benefit from slowing at least your "easy"  stuff way down so you can hit the quality stuff better. Also, be sure you're changing up the stimulus regularly too or you'll run into the same road block. If you're talking just running then google "Summer of Malmo", might be a good place to start and then build in some quality stuff later down the road. 

Rest easy. I can pretty much guarantee that you would have been a slower runner had you trained 'easier' in z2 with the same volume.

Unless you're at the far end of the overtraining curve (which I doubt you are, it usually takes a pure running focus, and over 10miles per day), there are no freebies for speed in running. The easier intensity z2 running is effective not because it's easier - it's because it allows you to run SIGNIFICANTLY more than had you burned your matches doing all z3-5 high intensity stuff which by definition you can't sustain for more than an hour continuously.  

There is no runner in the world who would be a better runner over a season if running, say, 30 miles per week at easier z2, as compared to 30 miles at early z3. I know, sounds like common sense, but it's easy to get confused with all the terminology flying around. 

Short-distance AG runners who bump up training volume to race a marathon often and usually break all their 5k-HM shorter distance race PRs in the training progress, despite doing mostly z2 training. But they do a LOT more z2 training than had they been running for their typical 5k goal race, often double their weekly mileage. Doubled mileage at the AG level usually trumps a whole bunch of high intensity work, with much less injury risk as well. That's the 'magic' of z2 - but you don't get anything free - you'll still feel dead legs and overall fatigue quite frequently when pushing up your weekly mileage volume. 

Thanks for the input.  Also kept looking into it myself and looked at some of the old plans I used for HIM/IM races.  Almost all say run/bike and stay in Zone 1-2.   I think I read that as BE IN HIGH Z2!  Forget about that Zone 1 stuff!  Another sign I may have been a little on the high side of my easier runs.

I'm going to stick with the Polar plan for the moment and stick around the Z1/Z2 border and see how I feel.

I don't think there's a real problem with even being in Z1, as long as you're not doing it to purposely make your efforts super easy, likely walking, or coasting whenever possible. 

The key though, is to INCREASE run (or bike) volume to the point where you start feeling the real beatdown from the lower-zone work. At my peak pure run training as a pure marathoner, I ran up to 100mpw (and averaged 85), of which 60% were probably Z1 or close to Z1 runs. Literally at 11-12min/mile, despite my race speed of sub-6 5ks and sub 6:30 for HM. My fast days were fast though, even though the total mileage/time of the fast stuff was <10% of the total weekly volume at that amount. Obviously as a triathlete you won't get anywhere near that, but the combined bike+run volume will beat your legs down at some point if you're doing it right, even if it's almost all z1-2 work.

If you don't beat down your legs at some point during that low-zone training, you're not going to improve anywhere near your potential.

This also doesn't mean you have to thrash yourself for weeks on end - pick an appropriate plan with appropriate volume, then DO it, even when it gets hard, as that's when most of the improvements occur. (Yep, right when you think you're probably overdoing it. But if your in z1-2, it's as safe as you can get.)