The Next Level: Marathon Training with Coach and Former Pro Martin Grüning

About a year ago, I broke the magical three hour barrier in the marathon run.

It did not come easy to me, I had to work for it over quite a few years until finally everything came together.

In regards to my fitness, I was certainly at an all-time high and managed to again run a sub three marathon just a few weeks later and also broke my personal best in the half marathon distance, reaching 1:22:01 hours between both. Being this fast felt amazing!

🔀 But where to go from here?

I’ve been running for around fifteen years now and spent most of the time just for the pure joy of motion, as opposed to the competitive aspects. Speed didn’t interest me that much for the first ten of the fifteen years. I never did any intervals during that time, for example.

When the bug then bit me to go and see how fast I can become, over the course of a few years the “Sub-3 Marathon” goal appeared around the beginning of the year 2020.

I gave it some thought about what could come next and arrived at an early conclusion that a marathon that fast should certainly be enough. I might stop chasing personal records in the distance when that milestone is reached. Maybe repeat the same pace at some more races over the coming years, but not more. After all, the effort you need to put in grows exponentially while the returns keep diminishing.

But that was before I learned how good it feels to be able to run so incredibly fast – “incredible” from my own former point of view. How can you know something you haven’t experienced yet?

After breaking three, some months went by where I didn’t think about it much. Until at a weekend in October, in a metro carriage in Chicago, while sitting next to some young folks who were smoking weed and annoying a homeless who was trying to get some rest into pulling a knife on them, my friend Nico screamed at me because of the loud noise of the old and broken vehicle, stating that anyone our age can run a 2:45h marathon.

What a preposterous hypothesis!

Debating him, the talented runner who had just done a 2:34h marathon in Berlin a few weeks prior after taking up running just five years ago, I realized I was on the losing side of the discussion. Not only that, I myself was falling victim to something I often told others to avoid: The Limiting Belief.

→ Yes, there is more potential in me. And also yes, running super fast feels amazing.

Another thing that benefits if I keep trying to get faster on marathons are my ultra marathons. Not only the new rising star David Roche is aware that speed on the short distances helps a lot with the really long ones. And I knew I will probably keep both in my annual racing plans because I just enjoy it all so much.

“I want to get faster” is a bad goal, though. Same as “I want to lose some weight.” You need to put a hard number on it so you can define and follow a clear path toward it.

Going for 2:55h from my personal best of 2:58:44 didn’t seem like worth the effort and it’s not exactly shooting for the stars. Setting big scary goals increases the chance of following through. On the other hand, you don’t want to overdo it and risk injury. I remembered the rule of thumb that stated you can safely aim for a 5% increase year-over-year when talking about your personal marathon best.

Five percent faster than 2:58:44 equals to 2:49:47 hours. Sub 2:50h! Then I looked at the pace that’s necessary to achieve this result. And it’s 4:02 minutes per kilometer. My next thought might not surprise you:

Why not go for 4:00 minutes straight, then?

✅ There’s the new audacious goal.

I came up with that around November 2024. Next, I chose a race. The flat and fast Bienwald Marathon near Karlsruhe in southern Germany was a good choice for my first marathon breaking three, so I bought the ticket. It’s on in early March every year and would host its 50th edition in 2025. I liked it a lot last time.

🗓️ But What Should I Do About the Training?

Repeat exactly what worked last time, just run a bit faster? Certainly an option. But a boring one.

Enter my friend Martin Grüning.

We first met a few years back through mutual friend and runner Michael Mankus. Martin is not only a proper running coach who looks back on many decades of experience with a variety of talented runners, he also used to be a professional runner himself, maxing out at 2:13:30 hours on the marathon – international elite level at the time.

Last not least, he’s the editor-in-chief of Runner’s World Magazine’s German-language edition.

Most importantly though, he suddenly had an opening for coaching someone! In the past he had already offered to help me with more structured training, but now this was just perfect timing.

By now, I have seen and done many different running training approaches and I was curious what would set apart Martin’s idea of the best possible plan for me.

In the beginning, we met to talk about my individual situation and I gave him all the important info that he didn’t know yet.

• How many kilometers per week I usually run
• What my known weaknesses are
• What I do for nutrition
• Which training sessions seemed to have had the most positive impact on me in the past

And a bunch more.

Right off the bat, he had a few direct and easy suggestions.

• 📈 For a marathon in less than 2:50 hours, I should increase my weekly kilometers from my usual 80-100 to around 120 (about 75 miles).
• 🍯 Carbohydrates have been all the rage lately and everyone seems to be profiting a lot from increasing their intake during intensive endurance exercise. I should start getting accustomed to this right away and not forget to take my gels (or equivalent) for every run that’s longer than half an hour.
• ⏩ Some of the fast runners he coaches have seen large improvements from introducing the currently popular “Double Threshold” days – but with my kids at home this isn’t an option.

❤️‍🔥 Next Up: The Current Maximum Possible Heart Rate

Martin told me that although the many professionals he knows and sometimes works with often use lactate testing to see exactly where their fitness levels are at, relying on the good old heart rate has been making a comeback for a lot of them, too. I’m glad, because not only is lactate testing quite expensive, it’s also a real pain to stop during the high intensity runs for pricking your earlobe and looking at the measuring device analyzing your blood all the time. That’s just one step too much for a runner like me who is ambitious but still just treats it as a fun hobby.

For these reasons, Martin’s plans all heavily rely on heart rate specific workouts.

A workout that requires you to run for forty minutes at 80% of your maximum heart rate can only be done if you know your current beats per minute at 100%. And since my most recent test was over five years behind me, Martin suggested we do a new one together. That way he was also able to fill a page in his Runner’s World print magazine with my report on that experience.

🥵 I was reminded of how tough these tests are!

There are several different tests to finding out your maximum heart rate, but if done correctly they all end in the same way: with you reaching your maximum heart rate. And that feels like you’re not far from collapsing from exhaustion. On the other hand, it’s also a significant workout, helping in improving your fitness. But I’m glad you only need to do these every 3-5 years. The number I arrived at was 195.

Not long after, Martin sent me my individual training plan. I couldn’t believe it, but he actually filled out every single session manually. And proudly! He also once messaged me saying it’s really him, Martin, not the AI coach so many others are using these days.

🐘 Of course it’s the elephant in the room: Will AI coaching replace human coaching?

Frankly, I’m sure it will. Some will keep preferring the human touch, of course, just like some people still enjoy riding horses for fun even though we have replaced their primary use with cars long ago. I haven’t tested it yet, but for a huge number of runners, the many advantages of an LLM which knows all of your training history and all the world’s training plans will and possibly already do outweigh the countless human limitations. This doesn’t mean that the human connection that builds between two people who enjoy running will cease to exist, obviously it doesn’t need to. But anyone who thinks the human approach will keep leading to better results has no idea what the current software can already do.

Even when it comes to the emotional side of it, such as giving good praise when you’ve done a particularly difficult session, the AI can know what to say and when to say it, and research has shown how beneficial that has already proven to be for people. Even basic and mid-level therapeutic discussions work well for many.

This analysis might sound harsh to you, but this is just facing the facts. Of course denial is also an option; a popular one right now I might add.

Back to my present plan, crafted by a real human – as was tradition in ye olden times of yore!

Martin presented me with this custom 15-week plan. He usually does 12-week marathon training plans, but since our discussion started fifteen weeks before my planned race, he just went out of his way and added some “introductory” weeks at the beginning. Those really helped a lot in getting me ready for the tough sessions ahead.

But first things first.

💫 What Is Special About Martin’s Plan?

Nearly all marathon training plans have a few building blocks in common. These are three main sessions:

1. The weekly long run
2. The anaerobic intervals to improve your speed
3. The marathon race pace runs

Martin told me that in this regard, plans haven’t changed at all since the 1970s when he started running. It’s in the details.

🚥 Curiosity #1: The Hard Heart Rate Zones

In this plan, the zones are different to what I was used to. More intense.

The typical zones models differ a lot, depending on who you ask. Some use three, some five, some six or seven zones, but most will be familiar with a five zone model. Next, the range of the zones isn’t constant. This is not helpful. The Norwegians, who have had a number of prestigious successes in recent years in the endurance sports, have decided on one consistent model across all sports in their country – we should probably just copy this globally to end the confusion once and for all.

The most popular model is the one that divides the heart rate percentage ranges from 50% to 100% into five evenly spaced ones. Zone 1 is 50-60%, Zone 2 is 60-70%, and so on. People put a big emphasis on “Zone 2 Training”, by which they mean this lower intensity range, usually. Zone 2 in the Norwegian model is at 72-82%, by the way. They have to work harder for the easy runs all the time! Maybe that’s part of the key to their success.

But what about Martin and his Runner’s World model?

It’s more on the Norwegian end. You could also call it the tougher end, suited for faster runners.

But the names he chose are funnier:

1. “Langsamer Dauerlauf” (slow run): 70-75% of maxHR
2. “Ruhiger Dauerlauf” (easy run): 75-80% of maxHR
3. “Lockerer Dauerlauf” (relaxed run): 80-85% of maxHR
4. “Zügiger Dauerlauf” (brisk run): 85-88% of maxHR
5. “Schnell oder Tempoläufe” (fast or tempo runs): 95-100% of maxHR

Not only does he describe the zones in a condescending way, but there’s just nothing below 70%! That’s usually already a Zone 3 effort in the classic model, and here it’s basically treated like a recovery run.

Realizing this made me feel a bit uneasy. Will I be able to pull it off?

📶 Curiosity #2: The Intervals Tiers

This is just a slight diversion from what I was used to, and right away I thought this was smart. Martin has the typical 800m intervals once per week, as many do. The amount increases week over week as well, although he starts at eight and goes to ten – quite high. Before, I was familiar with going from four or six to eight maximum. But this is not what differed so much, it’s the pace.

There are three separate “pace tiers” in the plan. I was supposed to start the 800’s at a pace of 3:40 min/km (5:54 min/mi) and keep that for the next two weeks while increasing the amount from eight over nine to ten. Then, Tier 2 is unlocked: 3:35 min/km (5:46 min/mi) pace. Start at eight, next week nine, the week after, ten. And finally, Tier 3 with a pace of 3:30 min/km (5:38 min/mi). Again toward ten.

I tried talking Martin into changing this to the more modern approach of using time based interval units instead of distance based ones, but he insisted on keeping it the old way – the only argument he put forward was that my performance would be easier to compare in regards to the Yasso 800 principle. Fair point, I guess, and also not important enough to start a discussion about it.

🚄 Curiosity #3: Race Pace All the Way

Right in week one, there’s a 12k race pace run. We have those in every week from the start, and they are never short. I think that one was the shortest, and it went up to 4x 5k at threshold pace, which is around ten seconds per km (sixteen per mile) faster than marathon race pace even!

Many other plans put more emphasis on the aerobic capacity build-up by making you do faster shorter intervals such as the 800s during the first weeks before putting the marathon pace workouts on top of that in the second half of the training cycle. Here it happens all at the same time, and lots of it.

Okay then, bring it on!

🌶️ Curiosity #4: Spicing Up the Easy Runs

Even the easy runs are supposed to be harder here. As said before, that’s first of all because of the higher heart rate zones. But he also included the popular “strides” at the end of nearly every easy run. That’s several (usually three) little twenty second sprints where you go out to around 95% of your maximum speed for that timespan in a controlled way, putting emphasis on proper running technique. Hard to do a day after a hard run!

🏋️ Curiosity #5: No Strength, No Cross Training

His initial plan didn’t take that into account, but when I mentioned it both, he gave in and included it for me. If I hadn’t said anything, it wouldn’t have been in the plan. I was under the impression that it had been well established that both strength training and other sports such as cycling and swimming, or even Yoga, were benefiting running fitness if added. Martin knows about this, but he’s a purist. He says that only running more will make you better at running. He’s not alone there.

I’m not so sure, especially if you take a look at what many professionals do these days. And I myself made tremendous progress last year by utilizing the additional weekly anaerobic workouts on my stationary bike without jeopardizing my joints. Some more strength training would certainly help me and my running form, too. I’m not the strongest guy. But with both, he left me alone. He’s a running coach, after all.

🪨 Things That Weren’t Unusual

Remember, this is my personal experience. Run training is highly individual and coaches do lots of different stuff. We can only ever see a fraction of what happens. What might be unusual from my point of view could have been someone else’s staple session for years.

• The long runs started with a moderate distance and increased over the weeks. Pretty standard practice. At the end we arrived at 38 kilometers, which is the higher end of a long run. He often mixed in some faster parts (according to heart rate) during the end of the long runs – but that’s also what I consider to be the usual.
• The plan is divided into three phases of four weeks each. Of those four weeks the first three are a build-up and the fourth is a regenerative week where you relax a bit and let the body adapt. This cycle seems to work well for our human rhythm and I’ve seen this a lot before.
• Ten days before the race, training will wind down in what’s a classical “Tapering Phase” – here, I have seen other ideas work well, too. But the standard still is to relax during race week to make you full of power for the big day.

💬 What Do Other Coaches Say About the Plan?

It’s always nice to get some additional perspectives on something that can seem as arbitrary as a marathon training plan. After all, there are many different paths that lead to the desired effect – a new personal best in the marathon – but coaches don’t always see eye-to-eye. At least that’s the case in my experience. I am in the lucky situation that I have a handful of certified running coaches in my social bubble and I talked over this plan with a few of them.

To my slight surprise, none of them were bold enough to call out this plan as worthy of big improvements or lacking critical elements. I guess that knowing it has been written by Martin Grüning himself gave it some credibility from the get-go. I should have probably hid that fact when asking opinions!

One thing that all the coaches I showed this plan to agreed on, though, was that it’s a tough plan. It doesn’t take any prisoners. That’s implying there are ways to reach the same goal with less effort. Of course, that’s always a gamble – but so is taking on a tough plan and getting through it in one piece.

Only one way to find out, and that’s going all in.

🚀 Starting the Experiment!

The first two introductory weeks showed me what was lying ahead of me. Tuesdays, there were pace pyramids on the menu (1-3-5-7-4-2 minutes fast by feel, 1-3-6-9-6-3 minutes the week after), on Thursdays I had to do progressive runs: 30 minutes at 70-75% maxHR followed by 40 minutes at 80-85%, and finishing off with 20 very fast minutes at 85-88%. Saturdays had a long run each at 20-25 kilometers (12-15mi), but to be run at 80-85% – rather high for my standards.

The remaining days were filled with short and easy runs. Additional strength training on Mondays and a cycling workout on Sundays.

That’s the first two weeks. I got through it alright, but it already took quite an effort.

Especially the high heart rate zones were exhausting me a lot more than I was used to. They also resulted in faster paces, obviously, and that surely felt good.

When I talked this over with Martin, I learned something new from him.

So far, I had been under the impression that the optimum heart rate that can be sustained over the full marathon distance is at around 82-86% of maximum. And that the key to improving marathon fitness would be to reach a level at which you just run faster at that same heart rate.

But that’s not the complete truth, according to Martin.

The point of the training is also to be able to hold a higher heart rate for a longer time!

He said that the marathon heart rate we’re aiming for is 85-88%. Very high, for my taste! For a half marathon maybe, I thought. But no, I’m in it now, so this is the new goal. Turns out, the more professional the runner you’re looking at, the higher percentage of their maximum heart rate will they likely be able to sustain.

To understand this, you also need to take into account the difference in absolute time that you require your body to run at that high effort when comparing amateurs to professionals. The cumulative power output over two hours is very different from the output over three hours, or even four hours, for that matter. Running a four hour marathon at 85-88% of max heart rate is likely not even possible for anyone, but the elite who run for just two hours will even go to 90% and beyond – because it’s a lot less total time they need to keep it that high.

When I realized this, I got a bit scared. That’s because I know what 85-88% feels like, and it’s not a walk in the park by a long shot. On the other hand, I knew what training can do with our perception of effort, so that would probably change.

After these two introduction weeks I felt like I was already on fire! If there would have been a race in a week, I think I might have been able to run under three hours. That’s the muscle memory my body was able to reactivate, I think. The heart is also a muscle. All the kilometers I have put into my legs over the years have added up to a great and stable base I can build on.

The stationary Zwift bike sessions have given me a real boost just like they did last year, but the strength sessions were difficult to add on top of the sore legs. Especially since Martin put them on the day right before the fast speed workouts, I was reluctant to go all-in so I wouldn’t risk running fast on stiff legs. This didn’t fit well, but there was no other option, Martin said. According to him, the most important run of the week is the race pace one on Thursdays, and I should not go into that one with sore legs, he insisted. I’m sure that’s where some other coaches would defer – because sore legs on the speed intervals most definitely add a higher risk of injury. It’s tricky to balance perfectly.

Still, my motivation was at a high after these two weeks.

📈 The First “Real” Weeks

I couldn’t wait for the 800m intervals to start. Also, I was very interested to see how I would perform on the race pace workout in regards to my heart rate. The long runs are just pure joy for me, but not very interesting from this experimental point of view: I would just go out, run for the required amount of time, and come home more fit but with no new lessons learned.

🔁 Starting with the 800s.

A whopping eight times at a pace of 3:40 min/km. And that’s where we start!

This had been the master interval session last year for when I wanted to “just” run the marathon in less than three hours. But we’re aiming for 2:48-2:49 hours now, so it’s crazy to see what a difference this makes.

Doing these intervals in the cold Hamburg December on a windy stretch along our Elbe river isn’t the easiest of tasks, but I managed to do all of the repeats within the numbers. From a pure speed point of view, a sub three marathon would have been possible next week, I think.

⏱️ Two days later, the first race pace workout.

The task was to run for 12 kilometers (7.5 mi) at the planned race pace just to see where the heart would go right now. I fought quite a bit and landed on a 3:59 min/km average – right on point. The average heart rate was at 89% though, and while that’s just slightly above the 85-88% corridor, the difference is noticeable. It felt like a race effort. The goal is to make this pace and heart rate feel almost easy over the next few weeks. It was a good start, though.

🛣️ And the Saturday long run can’t be missed, either.

An early start due to family obligations was required, so I went into this one tired. I also experimented with carbohydrate mixtures and tried a 2:1 fructose to glucose ratio today, quite unusual. It didn’t feel good in my stomach, better stick to what works well next time. This session consisted of 25 kilometers (15 mi) at easy pace, followed by three (2 mi) at a heart rate of 85-88%. I struggled to get into that zone in the end and landed on a 84% average over those last few k’s. That corresponded to a 4:15 min/km (6:50 min/mi) average pace, which at that heart rate after 25 kilometers on the feet was quite good in my opinion, especially considering the bad carbs mix and early start.

So this is what the next three months will mostly look like.

I felt okay, albeit with tired legs.

🫚 Nutrition and Supplements

During this time I also paid close attention to nutrition to make sure I put myself in the best possible position to succeed. In addition to my usual high-carb vegetarian way of eating, this included a bunch of anti-inflammatory foods such as ginger and honey, but I also started drinking loads of beetroot juice. Its high nitrates content is known to aid in better blood flow, reducing oxygen cost, and improving mitochondrial efficiency. Side note, non-organic beetroots have an even higher content of nitrates. So there’s a little dilemma for you.

In addition to that, I upped my daily supplement game rigorously. After my runs, I have a vegan protein shake with a drop of Vitamin B12 concentrate and three pills: one for iron, one for Omega-3, and one containing zinc and selenium, boosting my immune system during these cold winter months where lots of people get sick. Vitamin D mustn’t be skipped, as well.

Also worth mentioning, in my family of six, we all got the season’s flu shot and some of us had the newest Covid shot as well, including me. Three years ago, when I was also training for a fast marathon during the winter, I annoyingly got sick six weeks before the race. The year after, I had a few badly timed colds as well during training.

The combination of high intensity training, the cold and wet weather, and having four small children who are exposed to a total sum of hundreds of kids daily at school always makes this a walk on the knife’s edge.

My wife, a general practitioner who works with dozens of sick patients each day, always wears a mask at work during these months when so many people get sick, reducing the additional risk but not eliminating it completely.

I know from some professional athletes who reduce contact to possibly sick people during the weeks before important races to near zero by even moving out of their homes for that reason. Self-imposed isolation. When your salary depends on you being 100% healthy on Day X, it makes sense. Everyone else, including me, has to draw the line somewhere else.

It’s just a hobby, after all, but it’s still annoying to have your months-long efforts crushed by catching a bug at the wrong time. #foreshadowing

Next week I tried the newest rage, creatine. It supposedly helps with muscle recovery although the science isn’t completely conclusive there yet. For some, it can have the side effect of making the body store more water than necessary. I was one of those unlucky ones. After a few days of taking it, I was two kg’s heavier and could feel the water in my legs. Not the benefit I was hoping for, so I stopped that. The additional kilos disappeared in no time.

🌱 Settling Into the Rhythm

Training continued really well. Martin wasn’t happy that I always went beyond and ran the intervals and tempo sessions a few seconds faster than in his plan. He has the opinion that one should do exactly what’s on the paper. I do not agree with that, because in the end it’s about the effort you put in and not the seconds. If I’m having tailwinds and run three seconds faster on the 800m interval, that’s just smart training. He was worried that I would overly exert myself too early on. We would have to agree to disagree on that.

My fitness curve further improved while I still felt like it would be no problem to continue with this tough plan. And that’s what counts in the end.

After three of these standard weeks, or five including the two introduction weeks, the first regenerative week was reached. Block one of three done! That’s been a nice milestone, and it also fit very well with a family holiday trip during Christmas time we did to Denmark. The icy winds and snow up there did not make me feel like running as hard as possible anyways.

Family vacations are wonderful, but they demand a lot more energy – it’s a whole different challenge than the structured rhythm of our usual school-days.

🏁 The Test Race: “Winter Lucky Dip Run” in Staines, UK

Martin didn’t suggest this specifically, but I wanted to see if my newly gained fitness would already suffice to reach a new half marathon best, and since I had a trip to London coming up in mid January, I looked for a fitting race during the time, found one, and booked it. Martin didn’t have any objections. A fast half marathon is a great tempo workout to put into marathon training. He changed the training plan slightly to make sure I wasn’t going into the race on legs too tired and would have enough space to recover afterwards. He also suggested I go at it bold, because it doesn’t matter in a test race like this. If I explode at some point, that’s no issue in the big picture.

In the middle of the second of the three training blocks, I took the train from my London hotel to the little suburb of Staines-upon-Thames. Temperatures were around the freezing point, but it was dry and there hadn’t been any snow. The course is completely flat and just goes up and down the Thames three times. It was a tiny event hosted by some friendly enthusiasts. You were allowed to run as many of the 7k laps as you liked.

Before the race, I had finally given in and found a good deal on the fastest shoes on the planet, the Nike Alphafly 3 – both the current men’s and women’s world records were run in them. My plan was to start running at a 3:50 min/km (6:11 min/mi) average and see what I could do over the second half of the race. The dream would have been to reach a 3:47 average for a finish time of under 1:20 hours. And since my current personal best from a year ago stood at an average pace of 3:53, I thought this wasn’t too crazy.

It started off well, but I noticed I wasn’t in the perfect condition for reaching my dream time after around 5k. A stretch of 300m on mud with a Strava segment called “Horrible green hexagons” really messed with me and my balance on the fast pace in the new shoes. Since the lap was a out-and-back one, that’s 600m per lap, three times, meaning 1.8 kilometers or almost 10% of the whole distance to be run on slippery mud. The icy temperatures and pedestrians we all needed to navigate around didn’t help, either. So I lost my speed due to the higher energy demand over the course of the race. My slowest split was a 3:56 minute kilometer, so it wasn’t that bad. My heart rate slowly went from 87% up to 92%, which is perfect for a half marathon.

Regarding my personal best, this was a mixed bag in the end: I reached the finish line after 1:22:19 hours, which is 18 seconds more than where I stood, but the total distance was 200m longer than the 21.1 standard, so my watch and Strava claim a new personal best at an average pace of 3:52 minutes per kilometer or 1:21:29 for the half marathon distance. The official result is more important, so that’s unsatisfying.

But it surely was a very good workout that has helped me raise my fitness level yet again toward the bigger goal. The people of the Saturn Running club who put this together were very friendly and I didn’t mind hearing lots of Brits calling out things like “you’re absolutely flying, mate!”

Funnily enough, I won that race by over half an hour. That’s because there were just fourteen participants in the half marathon distance and the attitude of most is to just get in a good workout surrounded by friendly people who provide proper timing and a little aid station. Same for me. In the end it counts as a success.

🤔 Doubting the Plan

The remainder of the week in London didn’t go great from a training point of view, though. The half marathon and all the walking through the city put a lot of stress on my legs. But I was also starting to doubt some of the sessions, especially the 10x800m I had to do three days after – a classic, nonetheless.

But is it really so much more effective to do 10 repeats instead of maxing out at 8 of them?

With the race and all the walking in my legs, I succeeded with this week’s pace goal on 6/10 and missed the other 4 by a few seconds although giving it all I had in me that day – and wearing the super shoes.

Back at home, a 36 kilometer (22 mi) long run was on the menu, the last 3k of it to be run at 85-88% of max heart rate again. I did the full distance, but slowly, and had no energy left for going faster at the end. Had I reached my limit?

Why such a long one after a week like this? Wouldn’t a 30k with 2x5k at race pace have been better?

That’s the problem with all training plans, though. You can never know what would have been the best possible training session at any given day. It’s always just an educated guess based on the experience others and yourself have. During the times when it gets really hard, the doubts are amplified and it’s difficult not to throw in the towel or claim that the plan sucks.

But Martin was very understanding during these times. He helped me put things into perspective and had some encouragements ready to go. He reminded me that it’s part of marathon training to go through lows, and that not getting to 100% at some sessions doesn’t mean it’s the end. In fact, he was amazed at how well I had been doing so far compared to many others he’s coached.

It certainly helps a lot hearing that.

And what helped as well, was the second regenerative week up ahead. Finally!

⏳ The Final Stretch: Block 3 of 3

Once again, pausing the intense sessions for a week and only doing easy runs did wonders. But I still ended up collecting over 100 kilometers that week, mainly because I just love running so much and also because I was invested in the #EverySingleStreet running project – more on that in another blog post. The easy week also allowed for some more cycling, benefitting me some more. During the past weeks I had no energy left over for that, regrettably.

Firing up the oven again for the third and final hard block consisting of another three tough weeks was no problem at first. The Tuesday 800s have now reached their final tier with a pace of 3:30 min/km and I managed to pull them off perfectly. Two days later, a massive tempo run:

Four times 5k at threshold – that’s even faster than race pace. I did them in an average pace of 3:49, 3:48, 3:48, 3:53 minutes per kilometer (around 6:10 min/mi), surprising even myself with that. A few years ago it had been significant when I managed to run faster than 4:00 min/km on a single one of those 5k’s. Training works!

As great as it felt to run this fast for a total of 20 kilometers, I’m not so sure about this session in particular. It might do more damage than benefit. Most other plans I know break apart the race pace efforts into longer intervals like here, but they wouldn’t go over the top by increasing the pace that much. The result was that two days later my long run was a drag. I had very little energy left for it and my legs felt like they were made out of concrete.

I think at around this point I made the decision to do another fast marathon training cycle next year, no matter what result I’ll achieve with this one, just because I thought that I could make a better plan for myself, knowing my own body and its limits quite well now. It’ll be another experiment to see if I’m correct in that assumption.

💭 Plateau or Part of the Deal?

My personal feeling was that I would have been able to run the 2:49h marathon this week or the week before. I don’t think the third training block added much benefit to my individual situation, it might have even done the opposite and tire me out some more. Martin told me that tiring out my body is part of the deal, because it trains the body to find those last bits of glycogen and utilize them. Maybe he’s right, but maybe there are other ways, too.

The week after, I had a 18k race pace run on the plan and that one worked like magic.

I averaged 3:57 min/km and spent the most time of it in the 86-88% heart rate range, so exactly where Martin said I should be during the race. During last year’s Bienwald Marathon where I did my personal best I started out at 82-83% and only during the last thirty minutes reached 87% – that felt incredibly hard back then, though.

Now, it didn’t! I guess that is what Martin has been talking about: The intense training which is designed to tire me out to the limit leads to my body becoming more comfortable with a higher heart rate over a longer amount of time.

After the 18k at the high heart rate and pace I felt so good I could have easily gone on for another hour or more – quite probably even the full marathon distance.

Three days later, the last really long run with 38 kilometers (23.5 mi) happened. I ended up with 40.5, so I did another lap around the block to have a full marathon distance in the books, just for the heck of it. No problem. I have this in the bag, I thought. Never had I been as fit as I am now. The chances of success are nearing 100%. Four months of hard work are behind me, it’s time to reap the results.

I can’t wait for the race!

🤒 But Then, Life Happened

Two weeks before race day, I caught the flu.

No matter how many nutrients I put into my body or how smart my recovery was done, some things just can’t be averted. The flu shot I got was almost five months in the past now – the protection window had faded. It was such a huge bummer.

For a few days, I crawled around the block for thirty minutes – a poor excuse of a run – just to see if I was improving. It didn’t feel great, to say the least. I had no fever but I was highly exhausted all day and couldn’t sleep well. In the week leading up to this, two of my kids were sick too, with differing symptoms that included fever.

I hadn’t given up on the race yet, but the timing was just the worst.

That final 10x800m session at the last pace tier of 3:30 min/km had to be skipped with no replacement. And the ten days of tapering turned into ten days of convalescing first and foremost. I did feel some improvements, probably because I wanted to feel them so much. Mind over matter. Four days before the race, the plan suggested one last race pace effort of six kilometers, which I managed to do, but barely. My health was on the way up and the pace worked out, but the feeling of comfort was nonexistent compared to the fast runs during the past few weeks.

Still, each day was a bit better so my hopes were rising. After that race pace test I was sure it wasn’t the worst idea just to try. To see how far I can go.

🫠 The Bienwald Marathon, Planned as the Big Finale

My friend Guy and I travelled to the southern Pfalz region of the country with similar pacing goals. He hasn’t been sick and was optimistic about today – his first try at sub three, but he knew that based on his fitness, he could easily go for at least 2:55h or even beyond and his coach Nico agreed.

The atmosphere here was great for the 50th anniversary edition of the small race, not far from the French border. Weather played ball as well – sunny but not too warm, no winds.

I was hyped and really looking forward to the race. I knew from experience that my body has the potential to fully recover from a few days of sickness in a heartbeat. I was hoping this was the case today, too. And what’s the worst that can happen? If I get too exhausted, I could just stop or go slower. The risk of a myocarditis is looming over situations like these, but since I had no fever, felt no chest pain, no shortness of breath, and nothing about my heart was unusual currently, I didn’t think this was a threat.

🟢 Start of the Bienwald Marathon

Close to the front of the pack, Guy and I took off. It’s a great feeling to finally start the thing you’ve been anticipating and working toward for such a long time. I settled into the pace right away, and after a few kilometers felt mostly okay with it. Guy was behind me by a handful of seconds, as planned by him.

After around five kilometers, you settle into it. The adrenaline from the hectic start is fading, a little group of people that run your pace has developed, and your body usually moves into sort of a comfortable place.

Not so, this time. I still remembered how I felt a year ago at this point into the race. This time, it felt much harder. A look at my watch showed me that my heart rate had already gone into unsustainably high ranges. Nothing real crazy, but it was moving toward 90% this early into the race. Over the next few kilometers I slowly realized that this won’t work for the full marathon without a miracle.

But miracles do happen and I’ve experienced it many times during other races that suddenly everything feels lighter. Last year, my heart rate even went down from kilometers 15 to 25. Why not now, too?

So I kept pushing. When the half marathon runners, who had started at the same time, did their U-turn the field got very small. No pace group anymore. The person in front of me was fifty meters away, and those behind me, including Guy, too.

At kilometer 17, still bravely holding up the pace, I was at 92% of my maximum heart rate. Even for a half marathon, that’s bordering on too much for me. Huffing from exhaustion and getting sad when facing the reality, I kept holding this up for another four kilometers, until shortly after the half marathon mark, perfectly just under 1:25 hours, I got dizzy.

😭 The moment it all fell apart

Dizziness during a marathon race is nothing to joke about, I know that much. Over the years I’ve seen my fair share of collapsed runners being wheeled off in an ambulance and listened to horror stories of actual deaths happening, that I’m very familiar with the signs. When you get dizzy, you need to stop immediately.

It definitely wasn’t a lack of carbs, water, or sodium – beginner’s mistakes like those don’t happen to me. It clearly were the remainders of the flu I still had in my body. And I surely wouldn’t risk my health in such a way for a new PR. So I stopped to take measure of what’s going on. Not long after, Guy passed me with a confused but empathetic expression on his face and I shouted some encouragements at him.

The dizziness went away after stopping, so that was good. Here, in the middle of nowhere, with nobody around and all roads closed off for traffic because they were needed for the race course, no help was in sight. I knew that before. So I jogged on. At first, my body still wanted to go fast because I had settled into it, but over a few kilometers the pace continuously dropped. A fleeting thought about maybe still making it in under three hours passed through my brain but was disregarded really quickly.

Oh well, I’ll just jog this home then, I thought. I took an extra amount of time at the aid stations and suffered through the countless runners overtaking me. Then, weirdly, my legs started hurting. Everywhere. How can that happen?

Running slower was the only option as there’s no other way to the finish line. Eventually I had to walk for stretches. The pain intensified, but beaten and sad with an aching body I finally reached the finish line, accompanied by the amazing Guy over the last kilometer. He was extremely chipper, because he had just set a crazy new PR of 2:50 hours! A spectating girl shouted at him that she liked his colorful shorts to which he immediately replied “wait till you see my underpants!”, making everyone around laugh.

After 3:40 hours, I finally reached the finish line in pain and mentally deflated. Having the always positive Guy with me was great, but at the same time I felt like sitting in this emotional pit for a while. The negative emotions also need to be felt, I’m not brushing them to the side immediately.

☝️ But the story is not over yet.

Over the next few days, the pain in my legs concentrated on my left hamstring. This was new to me and puzzling, but confirming with knowledgeable people I found out it’s not that rare that muscle recovery will be hindered by the last remnants of the flu and can lead to injuries, too.

My first real running-related injury ever!

It will heal eventually, I was sure. I wasn’t going to give up yet. I still have a tremendous amount of fitness in my body, that had just been temporarily dampened and will eventually be available again. And many months ago I had anticipated something like this happening and now had an ace up my sleeve.

🇪🇸 Plan B: The Barcelona Marathon a Week Later

In just seven days, Barcelona would host their main annual marathon race. I knew long ago that having a backup race ready to go would be a good choice. And I’ve long wanted to do this particular marathon anyways.

My thinking was: If Bienwald works out, I’ll do Barcelona as a victory lap. And if it doesn’t, I’ll get another shot at the PR!

With the last bits of the flu now having fully left my body, but unfortunately still with an injured hamstring, Sophie and I flew to Barcelona while my parents took care of our four kids. A couple’s weekend getaway with a marathon race highlight for me. That situation alone lifted spirits.

I wasn’t sure what to do about the race in regards to my hamstring until the very last evening, when I spontaneously told Sophie at dinner that I’m going for it. Taking a risk despite the leg pain. It’ll heal eventually. I’m fit now. Who knows how many more opportunities I’ll get.

This time, though, I decided to run by heart rate in order to not repeat that same mistake as the weekend before. 85-88% all the way, maybe after 35k I’ll go above.

And what can I say: It went great. The race was amazing – highly repeatable! Conditions were perfect again – I tend to get really lucky in that regard.

During the first few kilometers I established what pace my heart was comfortable with today and landed on around 4:05 minutes per kilometer. That’s not the 4:00 straight that I had trained for, but at this point, I gladly took it. It felt comfortable – just as it’s supposed to. My heart rate settled at around 85%, I was glad to see. Everything was fine. The route is very good for fast races, too. Not as flat as Bienwald, but very flat. And having lots of runners around you also helps. This year’s edition had nearly 27,000 people running. You can draft for a bit and just let yourself get pulled by a group.

Spectating crowds do make a difference as well. The quiet at Bienwald has its advantages, but hearing all the loud Spanish cheering here made me very happy, too. ¡Vamos! And seeing Sophie a handful of times, just like in the old days when she and the kids would accompany me to most marathons made me very happy, too.

A total of four gels with 40g of carbs each was all I could comfortably handle today, and that was fine with me. The aid stations here were well stocked, too. I managed to keep the steady pace and crossed over the 88% heart rate threshold after 32 kilometers (20 miles). This late in the race, that’s absolutely okay. It’s supposed to be a battle at that stage, and that it was.

I dropped to around 4:08-4:09 min/km and starting from KM 39, even went down to 4:20-4:25. I had to give it all my effort now and put up a real fight. This late into the race, that’s also completely fine. Hard, but expected. And certainly no reason to be afraid – or to stop, for that matter. No dizziness today, that alone is reason to celebrate!

Crossing the finish line underneath that magnificent Arc de Triomf at high speed was the best feeling.

🕊️ Redemption.

With an official finishing time of 2:55:47 hours I was more than happy. Sure, it’s not the 2:49 or flat 4:00 min/km average I was dreaming of and aiming for with my training regiment, but given the circumstances I’m just super thankful to have been able to use my gained fitness toward a solid new personal best, shaving off three minutes of the previous one.

There’s room for improvement, always. And I know that I have it in me – once that hamstring is fully healed, that is.

And, not to forget, chances are very high that I’ll be able to qualify for the 2026 Boston Marathon with that finishing time. That’ll be so good. I can’t wait to run that race again. Together with Guy, and Nico, and maybe even some other friends.

📝 Concluding Thoughts About Martin Grüning’s Training Plan

A lot of heartfelt thanks belong to him. The way he supported me and the effort he put into it were highly appreciated.

I could have done a few things differently in hindsight – but that’s never surprising. If I had known before the Bienwald start that I was still slightly affected by the remains of the flu in my body, I would have skipped that race and quite possibly pulled off the 2:49h in Barcelona. But that’s a hypothetical and I’m not beating myself up about my decision. I did what I thought at the time was the right call.

Martin’s plan was hard and brought me to my limits, but it worked. Without the flu I am sure I would’ve reached the goal and maybe even been a minute faster.

Nearly all of the sessions he has in that plan made a lot of sense. But a few tiny things I will change next time.

1. First, that’s switching back from 800m intervals to 3:00 minute intervals. As stated before, by doing the classic distance every week and getting faster all the time, you’ll have diminishing returns at the later stages. Running the distance fifteen seconds faster per rep makes you lose out on ten times fifteen seconds of high effort. That’s two and a half minutes! If anything, this far into the training block you should go on for longer and not shorter efforts.
2. Putting more emphasis on VO2max improving bike sessions would also help me personally gain more speed and feel more comfortable at it. During most weeks I simply was too exhausted from all the kilometers to fit that bike ride in. And this is still my main bottleneck when trying for a fast marathon.
3. Less intense long runs. Some would be surprised to hear this, I’m sure. I’m doing ultras all the time, after all. But going for over 35 kilometers most weekends, often at higher intensities because of the prescribed heart rate, was too much I think. Not enough quality there. Here, it makes more sense for me to go by feel. Some weekends, easy 32 will have a good benefit, some days, when I feel like it, a full marathon will be better.
4. I’m not so sure what to do about the many threshold runs, though. Last year, I had minimized the amount of those and put most emphasis on improving my VO2max by doing shorter run intervals and the mentioned bike sessions, as well as the weekly low intensity long runs, and the result was absolutely perfect. Maybe I’m still correct in doing threshold or race pace only when I feel like it and not when I’m already exhausted but it’s in the plan. A few of the key sessions I’ll probably incorporate into my next blocks, like for example the 3x6k and 4x5k half marathon race pace ones. But I’m going to treat them more special by leaving more room before and after those days for recovery.
5. Listening to my body more. The problem with a fixed training plan is that lack of flexibility. Of course it can be done to just check off everything, but at what cost to the body? I think that by not paying more attention to my body’s reaction, I was also aiding in that hamstring issue in some way. Limits can be reached and crossed, and they need to be in order to be moved, but sometimes that’s not the right thing to do. It’s hard to notice when that happens, but with a fixed plan it’s even harder to say no to a session just because you feel a bit tired. Making up my own plan as I go along, based on the many different plans I now know, might be better suited.

I now have this plan under my belt, know how it feels, and can utilize its good ideas in the future. It has been added to my repertoire and enhanced my experience. That alone is worth a lot to me.

Marathon training is highly individual and without experimenting you won’t find out what’s best for you. Get started somewhere!