Zone 2

You might check out the Maffetone method--basically 180-age is your target HR for majority of training.  You have to really check your ego because it will feel very slow and yes, if going uphill takes you out of that zone you walk until it recovers.  It is a process and takes time but it works.  I've been steadily getting faster while keeping my heart rate around 133.  

#1 - Establish your zones correctly by TESTING, not with a calculator predictor vs age or other non-field test. HR zones vary a lot between individuals.

#2 - Once you're sure it's correctly established, sure, if you need to walk to keep your HR in z2, go ahead and  walk. I run marathons at close to 7min/mile, yet on the local trails with big hills, I don't hesitate to walk large sections of the climbs when I'm on a Z2 aerobic run.

this method is not helpful, you need to do a LT test.

Because it has no physiological basis.  It generally gives you a heart rate that is well below the top of zone two, and many people, especially newbies, won't be able to run in that zone.  A LT test gives you a real HR number to work off of.  My zone 2 tops off at 162 bpm, well off of this "rule of thumb"

A real new person shouldn't really even need to pay attention to this anyway.  If you're just getting into running just run!  5 days a week, don't exceed 10% increase from week to week, and run at a pace where you can have flowing conversation.  Don't even think about track workouts until you have a solid base.  and LB yes this doesn't apply to genetic freak children.

I say the same thing to people who just start cycling and ask about power meters.  Until you're comfortable on the bike and riding 100+ miles a week...just ride your bike.  Mostly hard, sometimes easy.

Maffetone isn't too different from others like the 220-age and others in that it works with a bunch of averages and come up with a very simple formula that has a tendency to be ok for a number of people. So it's not terribly surprising that a number will report that it does well for them, like some of the other formula based ones do. But there will be a fair percent that the numbers will be off for, too high or too low because all of them try to work with averages and don't have much in the way of standard deviation, or variation from that average.

The LT threshold testing tailors the effort levels to the individual based on their own physiology. It can take a few times going through the test, but they'll get there. I've seen people my own age 15-20 bpm below my own, and they have a decent idea of how to work. My HR just runs higher than average, but have also seen some who run a bit higher still. Under one of the simple formulas, all of us would operate at the same HR, but with the LT testing it will become specific to us.

From what I've seen of maffetone, it tends to be 100% easy, not just mostly easy. That can be fine for awhile, and should be how one starts out, but some faster work is a part of getting the most out of ones training.

And you're immediately dismissing this method because?

Perhaps because Mark Allen only won 6 Ironman World Championships?  Mark Allen himself gives much of the credit for those victories to the Maffetone Method.

https://philmaffetone.com/alleninterview/

As Mark Allen says in the above article - "I also think there is a certain amount of misunderstanding to his training philosophies. When you have a partial understanding about training your aerobic system and people say ‘How can you race well if all you do is train at the slow and steady stuff?’ First off, it is not about training slow. Second, he recognizes that you have to do speed work. That is part of what he tells you to do. People often miss that part of it. They are arguing against an incomplete picture. That is a classic example of what happens when people look at an isolated number and fail to see the whole picture. What Phil did was to see the whole picture. "

Dr. Maffetone has performed DECADES of field research to validate this method.  He has nearly 40-years of clinical experience and research in Sports Medicine.  While controversial, his methods are accepted worldwide.  He has published countless articles and research papers in virtually every medical journal out there - all of which were peer reviewed. With all due respect, I submit you might want to educate yourself on the Maffetone Method before you ridicule the program.

https://philmaffetone.com/method/

Careful lumping mine in with Dave's, and after lopping off a fair bit of what I said. I agree with the idea of going mostly easy, and that the easy is going to be slower than what people think it should be. Even with going 100% easy for significant periods of time. This is a really big thing that aspiring runners need to get.Maffetone probably does have a better regression line through his data than the other formulas for the easy running. Especially once putting in some other variances that often get left out. I've had difficulty in the past finding anything beyond running easy for it though. Well, sometimes strides are mentioned, but what else does he have? Mark Allen does speak of this, but seems this was in discussions directly with Phil more so than being put out with the formula. I'll be glad to work it into my thinking as it's felt like something was missing, but there are also other pretty good readings that haven't been as difficult to find. For example, the first ~15 entries in searching for it right now returned only variations of the 180-age, some mentioned the extra tuning, some mentioned strides.

Being you are reasonably fit, IMHO, you should do the field test (read this BT article) to find what your actual zones are.  It may take more than once to get it right but it will be worth if.  The number of times I did a field test from 2005 to 2014 my results were always within 3 bpm of one another.  But if I were to follow any on the xx0-age formula's I would have always been below my LT based Z2 range.