So how quickly does zone 2 pace improve?

Throw out hr bs if it feels easy it’s easy just be honest with yourself about what is truly easy. An easy run should feel better throughout the run. Just easy runs and a quality workout every 2-3 days. It’s not complicated

What is your 5k pace?

For a a well-trained runner, it doesn't.

Garmin heart rate, from my personal experience, isn't the most accurate. If you really want to use heart rate data, buy a chest strap. However, heart rate really is not that important for easy runs. Run by perceived effort/feel.

In my experience, a long time, and it varies with training load. In the past 2-3 years I've dropped from 23min in the 5k, to shooting for sub 19 in a few weeks. But truly easy pace only dropped from around 10:30/mi to 9-9:30/mi. Not an awkward shuffle anymore at least but still slow.

But the pace varies a lot. An avg run might start around 10:00 for a mile, then steadily drop to mid-high 8s by the end. Recovery jogs are still closer to 10. Moderate effort long run might average low 8s. For reference I ran a 3:18 marathon last fall and really I think marathon training did more for easy pace than 5k training.

Don't worry about HR too much, effort is king. Pace too, plug your 5k time into the tinman or Luke Humphrey running calc to get a baseline for training paces, but the marathon and easy paces might be optimistic

You need to know your max HR and use the chest strap in order to really use HR correctly. Garmin is setting your zones based on age.
I found the Mafftone formula of max aerobic HR on easy days to make the most sense for me.

Improving zone 2 pace is pretty touchy. Say you have a few days a week where you're doing Z2 runs. There's no question that you could do them a little faster week to week but the issue that at some point they become Z3 runs and you don't recover from them as easily. But you BS yourself and think your Z2 pace has improved.

You're better off not paying much attention to pace on those runs except to make sure they're really easy, and progressing your actual workout days instead. The pace at which you do your easy runs is one of the least important elements of your training plan as you'll only allow yourself to go so slow.

RunningFromTime:

Providing your age & 5k time will yield more specific & relevant info.

It sounds to me like you read an article or two that quickly developed some misconceptions, misinterpretations, hopefulness, ect...

IMO a pre-requisite for zone2 talk is reading through philmaffetone's website since many blog articles use that as there ref/source. Check it out.

This type of training is about TIME in the zone, not miles. Your heart&lungs do not know miles, they know time/duration. So throw out that 200mile figure and start thinking more in terms of time. For example your weekly schedule during base build phase could look like: 40min Z2, 90min Z2, 30min Tempo, 40min Z2, 100min Z2, 40min Z2, Then the mileage is what it is.

Without providing your real HRmax, any heart rate value you provide is relative worthless as there is no relation.

Zone 2 in which model? There are tons of zone models around.

Zone 2 or Zone 1 - this really does not matter much. Heart knows nothing about zones.
For me it usually takes about 2-2.5 months of consistent training to get to 7:40 mile pace/135bpm baseline indicating I'm fit. Starting from 10-10:30 at the same bpm, possibly even worse.

Cardiovascular system is easy to train. The big question is, can your muscles and joints support the training needed?

I'm not surprised this is a thread on this board, as incorrect as everything is.

But this sounds like a Broscience Reunion of Planet Fitness dropouts.

OP, if it's an easy run, and you think you're running easy, slow down. Run hard on your hard days. That's it.

To people wondering, I am early 30s and last 5k was 19:30. I have been running consistently for about 1.5 years but clearly did not know how to train for most of that. My attempt over the last few months of a real training plan left me fatigued a lot and my 5k did not improve from beginning of winter to just recently. I was doing my easy runs at 7:30 - 8:00 pace, which was too fast. I got the garmin only recently and my HR was in the 155 - 160 range on one of those "easy runs" meaning I have probably never actually done aerobic running or developed this crucial system in any way shape or form.

My max heart rate is 190 and resting is 60. For that obnoxious run I did yesterday, I used the calculation max HR * 0.7, which is 133 for an easy run.

That was too stupid, so today I instead used the heart rate reserve method. (max - resting) * 0.7 + resting = 151 so my "run" today was more reasonable 9:25 with an average of 142 bpm meaning I have a bit more wiggle room using this less conservative calculation

Darby, that is super reassuring that I can reasonable expect some gains in aerobic fitness over the summer. Hope I can make big strides in my 5k time come fall and then move on to 10k

Of note, the MAF 180 Formula gives me the same HR upper bound as the heart rate reserve calculation

This heart rate zone stuff is so stupid it physically hurts me to write this response, but somebody has to:

There is simply no excuse for being this misguided about your training.

Take back your power and start questioning the premises of this approach, not just the conclusions.

Well color me naive - want to expand a bit? Everything I read whether it's from Jacob's training to Wejo's summer trance that improved his 10k time after college + all the science interpretations I read emphasize the key to improving performance in endurance running is to build volume, the vast majority of it being easy. After my improvements plateaued and I realized I couldn't build volume due to being sore, I have started to learn what the term "easy running" actually means. Running 7 miles at 7:45 pace sure felt easy, especially relative to my tempo runs and workouts, but surely I was in the zone 3 region, accumulating lactate during my supposed recovery days instead of truly recovering and developing the aerobic system

Is that guy stupid too?

In my 20s, It took me 2 weeks of running at a sub 145 HR to drop 1.5 mins for 10k. 4 months later I dropped 20 mins in the marathon. It drove home the importance of easy running.

You could look into dfa alpha as a way to find your zone 2.

scientifictriathlon.com

DFA alpha-1: A non-invasive, cheap option for estimating the aerobic threshold with Bruce Rogers, MD | EP#329

Bernardo Gonçalves

Bruce Rogers, MD, is one of the researchers behind the research on using the non-linear HRV-based marker DFA alpha-1 (which can be be measured non-invasively and for free or very cheaply) to assess the aerobic threshold. We d...

Link:scientifictriathlon.com/tts329/

It seems that you're on the right track. Here's a trick that I have used to keep my HR low and keep my running pace faster on easy runs. Set your HRM to beep when you hit the upper boundary of your "easy" HR zone. When you hit that beep, focus on breathing a little deeper and relaxing. I've found that to reduce HR by one beat. If you get 2 beats above your easy zone, switch to a brisk walk. When you get to, say, 2 beats below your upper zone, start running again. Your walk will probably be less than 30 seconds.

Here is my rationale for this approach. As ViperDom pointed out, your heart doesn't know miles (or pace, for that matter). Your heart only knows time and effort so giving it this brief rest keeps your heart in its recovery zone on easy days. Your legs, however, DO know pace. There's a lot of difference in your form at 6 min/mile than at 10 min/mile. The more your easy pace mimics your race pace... in terms of form... the more race specific your workout becomes. And you can accomplish that with short breaks. I've done this by purposely adding walk breaks (5min run/1 min brisk walk) and found that at the end of a 4 mile run, my average HR was two beats lower than my normal easy 4 mile run and my time was only a 30 seconds slower than normal. If you do the math, my running pace was sub-9 when I was actually running.

Anyway, I've seen no studies to back up this approach. I don't think it would work for the marathon or half, but it should work for the 5k.