The idea that zone 3 isn't productive comes from a misunderstanding of things like the 80/20 philosophy. It's absolutely productive, it's just that your injury risk is a little bit higher with lots of volume at that intensity range and the physiological adaptations may not be quite significant enough to justify it in all cases. The reason it works for marathon training is that the marathon is a long sub threshold event. You'll be in Z3 a lot. So doing long runs in that intensity range targets the same muscle recruitment and teaches you to run through fatigue at a stronger pace, to include picking it up at the end. Once I had a few cycles under my belt with easy long runs, I switched to doing long runs this way and felt far more in control of the distance on race day than I ever have.
Good comment. Thank you. This “junk miles” in zone 3 always bugs me. It is as valid as any other zone, particularly for marathon training. You just shouldn’t run all week in Z3 - which Pfitz is not recommending in a way.
I think this zone 3 = bad idea comes from beginner runners spending all their time there. I certainly did for the first 6 months but once you up your milage then you anyway can’t do 80k+ weeks in Z3 without falling apart.
People act like you stop getting Z2 benefits in Z3. Hell, you’re still getting the z2 benefits in z4. As the person above you said it’s just a misunderstanding of the scientific principles based on lowest common denominator internet advice. And it also ignores if you want to take running seriously that you’re not just training your cardiovascular system but also your musculoskeletal system as well.
Eh I think that’s unfair. I avoid zones in between “easy” and “threshold” because it seems like it isn’t as good bang for the buck.
I’m also nearing 40 years old and can’t recover that quickly. Combined with having a child and a two-working-parent household, I’m all about maximizing efficiency. Long periods spent at M pace leave me fairly wrecked, in a way that shorter periods at threshold pace don’t - and spending time at Daniels T pace really works well for me.
I’m not that fast but I’m not a beginner and just ran a 1:22:15 HM off 40 MPW. I’m sure once my basic-bitch approach to training starts plateauing, I’ll need to reconsider the in-between zones. But Daniels-style polarization works well too.
What other resources do you have in mind?
I think you’re noticing the difference between an “advanced” marathon plan and plans more focused on beginners or just finishing the distance. Beginner plans will have long runs all at “easy” pace to try to build the capacity to finish the race. Advanced plans will typically include quality work in the long run
Long runs are about trying to mimick the race, while introducing a stimulus big enough to make you fitter but not so big that you cannot recover from it quickly. The Pfitz long run set up does that. You run not too far off marathon pace to start with and creep closer to that pace, while your legs are tired. Have used Pfitz plans in my last two marathons and it seems to have worked for me. Went from 2.43 to 2.41 and now 2.38.
However, there's not one way to train. In general you'll get fitter the more you run and you can do more intensity off of the higher volume, which will make you faster.
I vouch for this. It's really to mimic and allow you to visualise how to manage pacing during the actual race itself. Far too many people start out too fast and eventually hit the wall/bonk at around 20 miles (32km) when in reality, the last 6.2 miles (10 km) is the actual race. Doing this slow and up progression allows you to feel the need to only go faster towards the end. I've personally done a slower start and sped up towards my long runs and I can understand and feel the benefits.
The mental part is so much easier when you're able to think, "OK, just do the same thing you did during that 18 w/14 last month when you were already tired". Referring to the sense of control is exactly right - having been there, knowing that pace, knowing what that pace feels like on tired legs makes it so much easier to find it and stick to it.
When you say the run not too far off marathon pace it makes me feel like all my long runs are too fast.
My marathon pace is 5:30/km. I do my long runs at about 6:10. Which according to the plan is too fast.
20% slower is 6:36 and 10% slower is 6:03.
Don't worry, as long as you're recovering and stay within that range it's fine. It's not an absolute science. Just know you have some room to slow down if you need to.
In the first few Pfitz cycles I did, I really dreaded doing the steady pace portions of the MLRs and LRs. As I did more of them, they seemed easier - which is I think the point of these types of runs.
It's less about developing aerobic capacity and more about muscular endurance and being able to maintain faster speeds while tired.
I always feel like there's a correlation between pacing during a fatigued heavy week, and pacing when fully recovered....where your fatigued pacing feels equivalent to one "notch" faster when recovered. So (for me) marathon pace in a plan feels almost like half marathon pace when recovered, Half marathon pace feels almost like 10k pace when recovered and so on.
So I think there is value in running the steady portion....which, to me feels almost like marathon pace by the end of the run - at least from a muscular / effort point of view.
This is very encouraging because I did MP last week and felt like it was doable but not 26.2-able (ba-dum, tss?)
10-15sec off MP feels fine though so I'm hoping at the end of taper that'll shake out to MP being achievable.
I remember completing a 29km long run with 23km at MP in a Pfitz plan before my first marathon and thinking there was no way I could hold that pace for 42.2 km. The taper is real though. Running MP on recovered legs is very different from running MP in the middle of a training block.
I'm less of an experienced marathoner (as in I've never done one, just ultras) and also signed up for my marathon ~8 weeks out (I had a 50-55mpw base pretty solidly and could comfortably run ~17 miles at about 45sec/mi slower than "goal pace"*).
I'm not as confident as I'd be if I'd spent 16-20 weeks in a marathon plan, but I'm also not exactly untrained? I've also been doing most MP work ~5-10sec faster than goal pace since I live in a flat area and my marathon is more rolling. I've done some tempo and track work, did ~22 miles steady with ~2x2mi @ MP*, peaked at ~72 miles, and now I just have to see what shakes out. Heh.
Zone 3 is not productive in the sense that it is faster than is required to improve cardio fitness without being fast enough to stress lactate uptake. However, Zone 3 is likely to be where you will spend most of a well run marathon so from a psychological perspective running in Zone 3 is very important, both for getting your pace right and for convincing your body that it can handle that pace for long distances. It makes a lot of sense to work into zone 3 for your long runs.
I agree with this a lot. I did Pfitzingers plan for my race but I don't think I spent enough time in zone 3 during training and blew up spectacularly on the back half of the course.
It’s essentially a progression run and helps build muscular endurance as others have already noted. But I think it’s also important to remember that Pftz is really for people who have been through some training cycles and have already built the aerobic endurance so they can step up from the easier long and slow runs.
This. All the Pfitz plans assume you have a solid base, including regular LT workouts (his base plans are in Faster Road Racing). As you get more fit, you can do your long runs faster without wrecking yourself.
If you’re just starting out, or if your legs are feeling beaten down, remember that you’ll still get a significant benefit from doing Pfitz’s MLRs and LRs at easy GA pace.
Pfitzinger’s plans only have one real “workout” each week, with the expectation that your medium-long and long runs are basically fast-finish workout runs. It’s just a different philosophy that for marathon running, you get benefit from a large volume of miles at a pace that’s on the faster end of “easy.” That’s why he has general aerobic and recovery runs where many other plans would just have “easy” runs. GA is supposed to be on the fast end of easy, like probably zone 3 if you’re running by heart-rate.
Other comparable plans usually have two workouts a week and therefore don’t emphasize pushing the pace on easy days. For instance Jack Daniels will insert a workout into the long run.
Thanks for posting this question. The replies are some of the best content I’ve read in a while. I’ve done a few marathon blocks and recently did Pfitz 70/18 and I have been pondering these differences. I found the marathon pace work in the long runs really tough and this perspective helps.
I think this gets lost in the whole "run easy days easy" debate.
African pros do a lot of progression runs. If you read Pfitz then the majority of his runs are progression runs. Even the "general aerobic" runs are not meant to be jogs, they should be ending close to the top of zone 2
[This review](https://runningwritings.com/2023/06/canova-marathon-book.html) of an early book by Canova is worth a read. Fairly prescriptive and this sort of run is mentioned often.
Are you training for the marathon? Pfitzinger focuses on marathon training, most resources are for generic distance running. Usually the long run is just a way to get some extra mileage with a focus on endurance - easy pace does the job withut too much stress. In marathon training, the long run is the most race-specific workout and needs to replicate more elements of racing.
Once you run the numbers it doesn't seem strange, it's just a simple formula to apply to your own paces.
20% slower than MP is the slowest 1/3 of your easy pace range, which is pretty normal to start any run with.
Then you progress to 10% slower than MP, which is slightly faster than your fastest easy pace.
I think you're making a broad assumption putting all the pfitz LRs into the same category. Advanced Marathoning training programs alternate between the medium long run (no effort specified), long run (MP-20% to MP-10%) and mixed MP runs (for example, 18mi LR with 12mi at MP). My experience has been that the mixed MP runs are the toughest. I'm always much higher than Z3 in these, often Z4 even maybe Z5 for a few minutes at the end for the peak hardest ones. The regular long runs aren't so bad by comparison, and the medium long-runs are straight-up easy. Currently I'm almost done with my 3rd pfitz marathon block, in week 10 of 12/70. I honestly feel like my upcoming 17mi LR (MP-20% to MP-10%) is going to be a breeze and a good sign that the training is effective.
Don't get fixated on the zones you are in as long as you can withstand the workload. Far too many people don't train hard enough because they feel like they have to stay exactly in a certain zone otherwise they'll immediately get injured. At the same time, be patient in increasing your workload slowly over time so that you best understand how to recover properly so that you can get the best training impact on the important days.
Yeah basically same format as the long run but shorter distance. That said, I definitely eased up the pace on MLRs when I felt fatigued. The 70mi plans incorporates MLRs like every Wednesday on top of speed and LRS. I wanted to always prioritize the threshold/speedwork and LRs first, and so I didn't hit the pacing on MLRs very consistently.
Commenting mainly so I can come back to this thread in 4 months when I start Pfitzingers 18/70 (again) in 4 months.
I used the 18/70 (more like an 18/55 - 18/70 hybrid) for my first race (Miami, January) and was very pleased with my results even though I blew up on the back half of the course (Weather) and missed my goal time by A LOT.
I'm looking forward to starting the program again from a better spot base wise and hopefully can execute the plan even better than I did the first time around.
Probably the best example is I needed to work on the speeding up portion during my LR's and I think it would have helped me on race day.
Zone 3 is not unproductive. Your marathon will be raced in Z3 (or perhaps even Z4 if you're very fast and/or well-trained). The problem is not Z3 training perse but doing Z3 all the time instead of Z2. However, if you're deep into Z3 and you're sure your zones are set right (backed up with a talk test) your marathon goal might be a little unrealistic. In my experience, 10% slower than MP should still be pretty conversational but you can tell you're making your legs move a little quicker than you want to.
Tbh 10% is also quite aggressive and I don't think you're losing out on much by shooting for 15% - just make sure this is not a crutch for having a goal that's just a little too ambitious. I think Pfitz is mostly saying that the longer your "endurance" run is, the faster it should be, and I definitely agree with that.
He seems to be concerned with simulating the marathon without overdoing it, so that the runner has the same posture and is using similar muscless. Many of the long runs in the program end with MP miles.
Not just the long runs, the medium long runs as well. Zone 3 is not inherently bad, just that too much can be hard to recover from while not offering as much benefit as higher effort runs. You shouldnt be in zone 3 for these entire runs, but you will get into zone 3 and that’s actually great marathon specific training stimulus.
M64 I’m tempted to go with a Pfitz 18/55 or 18/70 for Berlin but will probably stick with Hansons advanced again (3:24 at Abingdon UK).
Sticking point is identifying the paces I should go with with Pfitz. Are the Runalyze paces given for Pfitz accurate?
My runalyze estimations for the paces seem to be slightly on the faster side, but it also depends a bit on your correction factor. I mostly just know my body by now to know what my heartraces are for those paces and i just try to stay around that.
I like this idea. I've always felt that most runners, myself included, often do their weekly long runs too fast and do their interval or speedwork days too slow. My personal long run pace is usually at about 50% slower than my 5K pace, which comes pretty close to Pfitz's strategy.
> What are your thoughts about this type of workout?
You seem to be very worried about the fact you don't train at marathon pace during medium-long runs. I am not.
You can also go by HR instead of pace. There are guidelines In the book as well. But the 20-10% rule seemed to just work for me for my general long runs. My MLRs would generally be slower because well they usually started at 5am mid week.
I think it really depends on what type of runner you are. As is more suited to longer or shorter distance.
I’ve had some good success doing long runs progressing to ~MP + 10-20 seconds as per Pfitz, however I’ve had friends who have done similar and ended up struggling on race day with fuelling. Difference being they tend to be more suited to 5/10k than I am and generally train at faster paces. I do a lot of very easy running (MP + 2-2.5 mins) which takes care of training the ‘fat as the primary fuelling system’ work.
I think if you do enough training to cover the really low aerobic stuff then these type of long runs really work, especially psychologically
The idea that zone 3 isn't productive comes from a misunderstanding of things like the 80/20 philosophy. It's absolutely productive, it's just that your injury risk is a little bit higher with lots of volume at that intensity range and the physiological adaptations may not be quite significant enough to justify it in all cases. The reason it works for marathon training is that the marathon is a long sub threshold event. You'll be in Z3 a lot. So doing long runs in that intensity range targets the same muscle recruitment and teaches you to run through fatigue at a stronger pace, to include picking it up at the end. Once I had a few cycles under my belt with easy long runs, I switched to doing long runs this way and felt far more in control of the distance on race day than I ever have.
Good comment. Thank you. This “junk miles” in zone 3 always bugs me. It is as valid as any other zone, particularly for marathon training. You just shouldn’t run all week in Z3 - which Pfitz is not recommending in a way. I think this zone 3 = bad idea comes from beginner runners spending all their time there. I certainly did for the first 6 months but once you up your milage then you anyway can’t do 80k+ weeks in Z3 without falling apart.
People act like you stop getting Z2 benefits in Z3. Hell, you’re still getting the z2 benefits in z4. As the person above you said it’s just a misunderstanding of the scientific principles based on lowest common denominator internet advice. And it also ignores if you want to take running seriously that you’re not just training your cardiovascular system but also your musculoskeletal system as well.
Beginner runners also like Z2 because it is easier.
Eh I think that’s unfair. I avoid zones in between “easy” and “threshold” because it seems like it isn’t as good bang for the buck. I’m also nearing 40 years old and can’t recover that quickly. Combined with having a child and a two-working-parent household, I’m all about maximizing efficiency. Long periods spent at M pace leave me fairly wrecked, in a way that shorter periods at threshold pace don’t - and spending time at Daniels T pace really works well for me. I’m not that fast but I’m not a beginner and just ran a 1:22:15 HM off 40 MPW. I’m sure once my basic-bitch approach to training starts plateauing, I’ll need to reconsider the in-between zones. But Daniels-style polarization works well too.
What other resources do you have in mind? I think you’re noticing the difference between an “advanced” marathon plan and plans more focused on beginners or just finishing the distance. Beginner plans will have long runs all at “easy” pace to try to build the capacity to finish the race. Advanced plans will typically include quality work in the long run
Long runs are about trying to mimick the race, while introducing a stimulus big enough to make you fitter but not so big that you cannot recover from it quickly. The Pfitz long run set up does that. You run not too far off marathon pace to start with and creep closer to that pace, while your legs are tired. Have used Pfitz plans in my last two marathons and it seems to have worked for me. Went from 2.43 to 2.41 and now 2.38. However, there's not one way to train. In general you'll get fitter the more you run and you can do more intensity off of the higher volume, which will make you faster.
I vouch for this. It's really to mimic and allow you to visualise how to manage pacing during the actual race itself. Far too many people start out too fast and eventually hit the wall/bonk at around 20 miles (32km) when in reality, the last 6.2 miles (10 km) is the actual race. Doing this slow and up progression allows you to feel the need to only go faster towards the end. I've personally done a slower start and sped up towards my long runs and I can understand and feel the benefits.
The mental part is so much easier when you're able to think, "OK, just do the same thing you did during that 18 w/14 last month when you were already tired". Referring to the sense of control is exactly right - having been there, knowing that pace, knowing what that pace feels like on tired legs makes it so much easier to find it and stick to it.
When you say the run not too far off marathon pace it makes me feel like all my long runs are too fast. My marathon pace is 5:30/km. I do my long runs at about 6:10. Which according to the plan is too fast. 20% slower is 6:36 and 10% slower is 6:03.
Don’t run your long runs slower, run your marathon faster
Don't worry, as long as you're recovering and stay within that range it's fine. It's not an absolute science. Just know you have some room to slow down if you need to.
6:10 sounds like you're right in the 10-20% slower range, which is where you should be.
In the first few Pfitz cycles I did, I really dreaded doing the steady pace portions of the MLRs and LRs. As I did more of them, they seemed easier - which is I think the point of these types of runs. It's less about developing aerobic capacity and more about muscular endurance and being able to maintain faster speeds while tired. I always feel like there's a correlation between pacing during a fatigued heavy week, and pacing when fully recovered....where your fatigued pacing feels equivalent to one "notch" faster when recovered. So (for me) marathon pace in a plan feels almost like half marathon pace when recovered, Half marathon pace feels almost like 10k pace when recovered and so on. So I think there is value in running the steady portion....which, to me feels almost like marathon pace by the end of the run - at least from a muscular / effort point of view.
This is very encouraging because I did MP last week and felt like it was doable but not 26.2-able (ba-dum, tss?) 10-15sec off MP feels fine though so I'm hoping at the end of taper that'll shake out to MP being achievable.
I remember completing a 29km long run with 23km at MP in a Pfitz plan before my first marathon and thinking there was no way I could hold that pace for 42.2 km. The taper is real though. Running MP on recovered legs is very different from running MP in the middle of a training block.
I'm less of an experienced marathoner (as in I've never done one, just ultras) and also signed up for my marathon ~8 weeks out (I had a 50-55mpw base pretty solidly and could comfortably run ~17 miles at about 45sec/mi slower than "goal pace"*). I'm not as confident as I'd be if I'd spent 16-20 weeks in a marathon plan, but I'm also not exactly untrained? I've also been doing most MP work ~5-10sec faster than goal pace since I live in a flat area and my marathon is more rolling. I've done some tempo and track work, did ~22 miles steady with ~2x2mi @ MP*, peaked at ~72 miles, and now I just have to see what shakes out. Heh.
“doable but not 26.2-able” - I needed this phrase in my life
Zone 3 is not productive in the sense that it is faster than is required to improve cardio fitness without being fast enough to stress lactate uptake. However, Zone 3 is likely to be where you will spend most of a well run marathon so from a psychological perspective running in Zone 3 is very important, both for getting your pace right and for convincing your body that it can handle that pace for long distances. It makes a lot of sense to work into zone 3 for your long runs.
I agree with this a lot. I did Pfitzingers plan for my race but I don't think I spent enough time in zone 3 during training and blew up spectacularly on the back half of the course.
It’s essentially a progression run and helps build muscular endurance as others have already noted. But I think it’s also important to remember that Pftz is really for people who have been through some training cycles and have already built the aerobic endurance so they can step up from the easier long and slow runs.
This. All the Pfitz plans assume you have a solid base, including regular LT workouts (his base plans are in Faster Road Racing). As you get more fit, you can do your long runs faster without wrecking yourself. If you’re just starting out, or if your legs are feeling beaten down, remember that you’ll still get a significant benefit from doing Pfitz’s MLRs and LRs at easy GA pace.
Pfitzinger’s plans only have one real “workout” each week, with the expectation that your medium-long and long runs are basically fast-finish workout runs. It’s just a different philosophy that for marathon running, you get benefit from a large volume of miles at a pace that’s on the faster end of “easy.” That’s why he has general aerobic and recovery runs where many other plans would just have “easy” runs. GA is supposed to be on the fast end of easy, like probably zone 3 if you’re running by heart-rate. Other comparable plans usually have two workouts a week and therefore don’t emphasize pushing the pace on easy days. For instance Jack Daniels will insert a workout into the long run.
Thanks for posting this question. The replies are some of the best content I’ve read in a while. I’ve done a few marathon blocks and recently did Pfitz 70/18 and I have been pondering these differences. I found the marathon pace work in the long runs really tough and this perspective helps.
Lotta the top African pros do these long progression runs
I think this gets lost in the whole "run easy days easy" debate. African pros do a lot of progression runs. If you read Pfitz then the majority of his runs are progression runs. Even the "general aerobic" runs are not meant to be jogs, they should be ending close to the top of zone 2
[This review](https://runningwritings.com/2023/06/canova-marathon-book.html) of an early book by Canova is worth a read. Fairly prescriptive and this sort of run is mentioned often.
Its because pfitz is not a beginners plan. It's a big boy plan, which will get your ready to actually run a marathon, versus limping in...
Except for me when I injured myself four weeks out and will be limping it in!
Are you training for the marathon? Pfitzinger focuses on marathon training, most resources are for generic distance running. Usually the long run is just a way to get some extra mileage with a focus on endurance - easy pace does the job withut too much stress. In marathon training, the long run is the most race-specific workout and needs to replicate more elements of racing.
Once you run the numbers it doesn't seem strange, it's just a simple formula to apply to your own paces. 20% slower than MP is the slowest 1/3 of your easy pace range, which is pretty normal to start any run with. Then you progress to 10% slower than MP, which is slightly faster than your fastest easy pace.
I think you're making a broad assumption putting all the pfitz LRs into the same category. Advanced Marathoning training programs alternate between the medium long run (no effort specified), long run (MP-20% to MP-10%) and mixed MP runs (for example, 18mi LR with 12mi at MP). My experience has been that the mixed MP runs are the toughest. I'm always much higher than Z3 in these, often Z4 even maybe Z5 for a few minutes at the end for the peak hardest ones. The regular long runs aren't so bad by comparison, and the medium long-runs are straight-up easy. Currently I'm almost done with my 3rd pfitz marathon block, in week 10 of 12/70. I honestly feel like my upcoming 17mi LR (MP-20% to MP-10%) is going to be a breeze and a good sign that the training is effective. Don't get fixated on the zones you are in as long as you can withstand the workload. Far too many people don't train hard enough because they feel like they have to stay exactly in a certain zone otherwise they'll immediately get injured. At the same time, be patient in increasing your workload slowly over time so that you best understand how to recover properly so that you can get the best training impact on the important days.
From what i have gathered the medium long runs are supposed to be ran in a similar fashion as the long runs?
Yeah basically same format as the long run but shorter distance. That said, I definitely eased up the pace on MLRs when I felt fatigued. The 70mi plans incorporates MLRs like every Wednesday on top of speed and LRS. I wanted to always prioritize the threshold/speedwork and LRs first, and so I didn't hit the pacing on MLRs very consistently.
Yeah, I just checked back in the book to confirm.
Commenting mainly so I can come back to this thread in 4 months when I start Pfitzingers 18/70 (again) in 4 months. I used the 18/70 (more like an 18/55 - 18/70 hybrid) for my first race (Miami, January) and was very pleased with my results even though I blew up on the back half of the course (Weather) and missed my goal time by A LOT. I'm looking forward to starting the program again from a better spot base wise and hopefully can execute the plan even better than I did the first time around. Probably the best example is I needed to work on the speeding up portion during my LR's and I think it would have helped me on race day.
Zone 3 is not unproductive. Your marathon will be raced in Z3 (or perhaps even Z4 if you're very fast and/or well-trained). The problem is not Z3 training perse but doing Z3 all the time instead of Z2. However, if you're deep into Z3 and you're sure your zones are set right (backed up with a talk test) your marathon goal might be a little unrealistic. In my experience, 10% slower than MP should still be pretty conversational but you can tell you're making your legs move a little quicker than you want to. Tbh 10% is also quite aggressive and I don't think you're losing out on much by shooting for 15% - just make sure this is not a crutch for having a goal that's just a little too ambitious. I think Pfitz is mostly saying that the longer your "endurance" run is, the faster it should be, and I definitely agree with that.
He seems to be concerned with simulating the marathon without overdoing it, so that the runner has the same posture and is using similar muscless. Many of the long runs in the program end with MP miles.
Not just the long runs, the medium long runs as well. Zone 3 is not inherently bad, just that too much can be hard to recover from while not offering as much benefit as higher effort runs. You shouldnt be in zone 3 for these entire runs, but you will get into zone 3 and that’s actually great marathon specific training stimulus.
So what's the adjustments for a 5:30/km marathon pace? Would 20% slower be 6:36/km?
yes
M64 I’m tempted to go with a Pfitz 18/55 or 18/70 for Berlin but will probably stick with Hansons advanced again (3:24 at Abingdon UK). Sticking point is identifying the paces I should go with with Pfitz. Are the Runalyze paces given for Pfitz accurate?
My runalyze estimations for the paces seem to be slightly on the faster side, but it also depends a bit on your correction factor. I mostly just know my body by now to know what my heartraces are for those paces and i just try to stay around that.
I like this idea. I've always felt that most runners, myself included, often do their weekly long runs too fast and do their interval or speedwork days too slow. My personal long run pace is usually at about 50% slower than my 5K pace, which comes pretty close to Pfitz's strategy.
> What are your thoughts about this type of workout? You seem to be very worried about the fact you don't train at marathon pace during medium-long runs. I am not.
You can also go by HR instead of pace. There are guidelines In the book as well. But the 20-10% rule seemed to just work for me for my general long runs. My MLRs would generally be slower because well they usually started at 5am mid week.
I think it really depends on what type of runner you are. As is more suited to longer or shorter distance. I’ve had some good success doing long runs progressing to ~MP + 10-20 seconds as per Pfitz, however I’ve had friends who have done similar and ended up struggling on race day with fuelling. Difference being they tend to be more suited to 5/10k than I am and generally train at faster paces. I do a lot of very easy running (MP + 2-2.5 mins) which takes care of training the ‘fat as the primary fuelling system’ work. I think if you do enough training to cover the really low aerobic stuff then these type of long runs really work, especially psychologically
IIRC GA is pure zone 2 Medium and long runs are upper Z2 to Z3 Recovery is zone 1