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For runners everywhere, the ability to hold and execute a 3-hour marathon pace is the holy grail of running. You become a member of the unofficial sub-3-hour club. For some reason, a 3hr 01 sec time won’t cut it either. if that’s the case, you’ll have to go right back and try it all again I’m afraid!

A sub-3-hour marathon is a bit like an elusive creature hiding in the jungle. It won’t just walk up to you two minutes after you waltz in there. No way, you’re in its environment, everything is against you, and everything is in the creature’s favor. To get that sneaky beast you’re going to have to go right out of your comfort zone. You’re going to have to prepare and change your mindset, like nothing before.

So, say hello to pain if you want to join that exclusive club.

3 hour marathon pace main image

Before proceeding

I fully acknowledge that the achievement of completing a marathon is a major accomplishment for the vast majority. In no way do I intend to belittle those achievements.

Before we get too deep into this you should know a little about my background in running. I’m a triathlete at heart, but I started as a runner. I’ve completed many long-distance triathlons. My half-ironman distance p.b. is 5 hr 01 min, the triathlon equivalent of a 3 hr 01 min marathon I reckon! It still haunts me.

At the time of writing, I have completed 1 marathon, a great many half marathons, and countless 10k’s and 5k’s. My own marathon time is 3 hr 26 min, coming 2nd, 10 min behind the winner. It was exceptionally hilly and it wrecked me, I was in bits for a good week afterward. It didn’t quite ignite a love affair in me for marathons. However, it gave me valuable insight into how tough long-distance running is both mentally and physically.

A change in goal dynamics

There’s a huge change in the type of goal you wish to achieve once you decide you’re going for sub 3 hours. For most (but not all), the usual path to this point will have been at least 2 or 3 three marathons completed. In the first one, the goal was just completing it – not likely to fail.

The goal for the second is usually to beat your one and only other time and set your marathon personal best – again unlikely to fail, you only need seconds to go better.

All subsequent marathons will be a little more difficult, but still only need small time gains to better the previous result. Psychologically it’s comfort zone stuff because it only requires going a little harder than what you’ve already proven yourself to be capable of.

Deciding on a sub-3-hour finish usually involves bettering your best time by many minutes. This, combined with knowing exactly what your pace needs to be throughout the race, can be a daunting prospect.

It requires a huge shift in mentality, and massive focus throughout the race, and your training. You’ll require greater strength of mind to achieve what you need to in training and the race. There must be no doubts in your mind that you can achieve that sub 3-hour marathon.

How fast is 3-hour marathon pace?

So to run 3 hours or less we have to do a little bit of calculation. I love this stuff!

  • 3 hrs = 180 min.
  • 180 mins = 10,800 seconds
  • marathon = 26.21875 miles/42.194988km
  • seconds per mile = 10,800/ 26.21875 = 411.9189 s (411 rounded down)
  • seconds per kilometre = 10,800/42.194988 = 255.9545 s (255 rounded down)
  • pace per mile = 411 secs = 6 m 51 s
  • pace per kilometre = 255 secs = 4 m 15 s

To put this pace into context let’s plug it in into some different race distance finishing times.

  • 3k = 1236 s =12 m 45 s
  • 5k = 2060 s = 21 m 15 s
  • 10k = 4120 s = 42 m 30 s
  • half marathon = 5400 s = 90 m

The closer you are to longer distance times, the easier this is going to be for you. It’s going to be a whole lot harder if you’re struggling to do 13 min for 3k, than if you are doing a half marathon in 1 hr 28 m.

Important components of a sub-3-hour marathon

In addition to the actual running required, there are some vital components to consider when training for, and executing a sub-3-hour marathon.

These are –

  • nutrition/fuel
  • rest and recovery
  • hydration.

The faster you intend to go, the more vital these elements are to incorporate correctly into your training and race plan.

You can do all the long runs etc you want, but if you don’t fuel and maintain your body correctly, it’s quickly going to let you down. Long runs are especially hard on the body. I personally find that anything over 90 mins starts to hurt in a different way than normal. Hydration levels will be much lower, along with fuel stores in your working muscles. The fatigue and damage to your muscles exponentially increases as you become more dehydrated.

Combine that with going too far past your current fitness level and it’s a recipe for disaster. This is also why it’s important to progress slowly with your long runs. Give yourself enough time to build up to your desired mileage.

Dehydration and pace reduction

Hydration really is one of the most vital components in executing a successful race. Neglect or underestimate this and you’re going to make it much, much harder for yourself.

Without even considering the negative effect on recovery, consider the effect that dehydration has on your pace alone. It is often stated that for every 1% of bodyweight lost through dehydration your pace will consequently slow by 2%. This is backed up pretty definitively by numerous studies such as the ones linked here.

However, even without those studies, common sense will tell you the getting low on liquids is inevitably going to slow you down. Especially when you consider that the average adult body is 50-60% water.

So, what does this translate to in terms of actual pace reduction then?

10k – 20k
  • Easily plausible to drop body weight by 1% at 10k, which is around the 42-minute mark.
  • So, 2% reduction in pace at 10k.
  • 2% reduces pace to 4.20 km pace, 5.1 seconds slower than 3-hour pace.
  • Assume unable to increase perceived effort, and this reduced pace is held for the next 10k.
  • 50 secs extra to complete 10-20k split.
  • 50 sec down in total at 20k.
20k – 30k
  • Bodyweight drops another 1%, to 2%, at 20k.
  • Further 2% reduction in pace at 20k.
  • 2% of 4.20 km pace is 5.2 secs.
  • Pace reduced from 4.20 to 4.25, now 10 seconds slower than 3-hour pace.
  • Assume unable to increase perceived effort, and this reduced pace is held for the next 10k.
  • 100 secs down in 20-30k split.
  • 150 sec down in total at 30k.
30 – 40k
  • Bodyweight drops another 1%, to 3%, at 30k.
  • Further 2% reduction in pace at 30k.
  • 2% of 4.25 km pace is 5.3 secs.
  • Pace reduced from 4.25 to 4.30, now 15 seconds slower than 3-hour pace.
  • Assume unable to increase perceived effort, and this reduced pace is held for another 10k.
  • 150 secs down in 30-40k split.
  • 300 secs down in total at 40k.
40 – 42k
  • Bodyweight drops another 1%, to 4%, at 40k.
  • Further 2% reduction in pace at 40k.
  • 2% of 4.30 km pace is 5.4 secs.
  • Pace reduced from 4.30 to 4.35, now 20 seconds slower than 3-hour pace.
  • Assume unable to increase perceived effort, and this reduced pace is held for another 10k.
  • 40 secs down in 40-42k split.
  • 340 secs down in total at 42k.

So, as you can see now, 5m 40s down at the finish, somewhere in the region of a 3 hr 06 m finish. That’s assuming your perceived effort holds flat from start to finish. It’s more likely to decrease, along with your pace, once mental fatigue from dehydration starts setting in.

Hydration solutions while running/racing

So, what’s the solution. You need to do something to counter this. You need to limit the amount of water you lose overall during the race. Keep in mind however, that it won’t be possible to replenish everything you sweat out.

It will more be a case of limiting the losses. Also, it is not a simple task to carry water with you while you run. There are plenty of options for carrying water, and I have tried many of them. Eventually, though, I found all of them to be annoying in the end up.

You see the problem is that even the comfiest and unnoticeable water carrier is NEVER, no matter what, going to be as comfy and unnoticeable as NO water carrier. They are all doomed to fail in this regard.

It’s important to accept the above point, before even trying to carry your own water while you run. It’s going to be a bit annoying for sure. However, it’s going to be way less annoying than becoming dehydrated and slowing in your race and long training runs. Just find the carrier that is least annoying and go with that. I personally use a belt that holds 4 small bottles, as opposed to a single larger one. Personal preference will dictate your choice.

How much to drink

In regard to how much, and how often to drink, it will really depend on two things. Firstly, how much you can carry with you. And secondly, how long your run is if it’s a training run. Unless you’re doing laps and refilling bottles then there’s a limit to how much you can carry with you.

My own method is to start drinking 30 minutes into the run, and then every 10 minutes after that. I aim to be finished with what I have more than 20 minutes from the end. How much I drink at each interval depends on how long the run is, and therefore how long I need it to last. You want to ration it for the length of the run ideally. Usually, I’ll have a mouthful or two each time. I wouldn’t take too much more than that, as it will only begin to sit in and swirl around in your stomach. The speed at which your body can process food and water slows the harder you exercise.

About nutrition/fuel and marathon running

This is another important aspect of marathon running. Even more important the faster you intend to go. Much like any form of transport, the faster you go the more fuel you use. You’ll get there quicker, but it comes at a cost, and that cost is the substance the fuels your muscles.

Fat is the body’s aerobic fuel source, it requires a high amount of oxygen to use. It requires more oxygen than you can supply at higher efforts. Think of it as your slow fuel.

Your body also contains another fuel type, glucose, and glycogen. These are the body’s anaerobic fuel source, they require no oxygen to use. You will use more of this type of fuel the faster you go. However, the supply is much more limited than fats, it runs out quicker. Think of this as your fast fuel.

To run long-distance races you will be using a combination of both aerobic and anaerobic fuels. The exact ratio will tilt one way or the other depending on your current speed, effort, and fitness level. You are unlikely to run out of fats at a 3-hour marathon pace, but you’re likely going to run out of your anaerobic fuels, your glycogen, and glucose stores.

Once your fast fuels have run out your pace is going to go downhill real fast. You will then only have slow fuel available. Think “hitting the wall”, or “bonking”. Those slow fuels are never going to keep you going anywhere near fast enough to sustain 3 hour pace.

Fuel options for sub-3-hour marathon pace

It is vital to keep the fast fuel tank topped up during training and the race. You can do this one of two ways. Either add a carb source to your water or take them in the form of gels.

I personally have used both methods fairly extensively, and I would steer toward gels. I tend to use isotonic gels, these are almost watery in texture. Some gels are quite thick and gooey in texture, and I would argue not ideal to take while running, especially at pace or racing.

My own experience with those gooey guys is feeling like I’m going to choke, and then needing to wash it down, and clear my mouth with a load of water. Not exactly ideal.

The isotonic, watery texture ones are much easier and quicker to take. To me, it feels more like drinking, which is exactly what you want when going at pace. A little bit of water is all that is required to wash it down.

The second method is to add a carb powder solution to your drink bottle. This is an easy and simple solution, hydrate and fuel at the same time. There is a limitation however, in how much fuel you can now take with you.

There will be an optimum mix rate for the powder, and adding more than this will start making the drink less effective in terms of hydration and fueling. It will also start to become stronger tasting and unpalatable.

I’m sure you can see it makes more sense to take one or two extra gels as extra ‘just in case’ fuel, as opposed to adding extra powder into your bottles.

How much fuel to take

Generally speaking, you will burn somewhere around 700 calories when running. This figure will differ based on a lot of different variables but let’s just go with 700 cal/hr.

Most gels usually contain around 100 calories, and up to 3 per hour are usually recommended. This works out at around 300 cal/hr. From experience, I would say this will be as much as you’ll be able to consume, per hour, without suffering stomach issues.

It’s never going to be a case of replacing 700 cal with 700 cal. It’s going to be a case of replacing 700 with 200 and so on. Just enough to stop you from hitting the empty mark before the finish line.

Also the harder you are going, the less you will be able to take. In training, I go with 2 per hour. However, when racing I’ll only take one every 45 – 60 min, depending on how hard I’m pushing.

There’s no point in taking in more fuel than your body can currently process. You just need enough to slow down the fuel loss, so you aren’t totally emptied before the end.

Aim to take the first gel at 30 – 40 mins. After that take one every 30 – 60 min depending on pace, and the last one at least 30 mins from the end. No point taking one 5 mins from the end. Also, if I’m racing I usually take one an hour before the start time, to ensure I’m topped up.

Try everything out before the race

It’s incredibly important to try out your hydration and fueling strategies before race day.

Test everything you plan to do during your race in training, never ever try new things on race day!!

I’ve heard so many disaster stories that all relate back to this problem – encountering something on race day you aren’t familiar with. I rarely have sympathy for any of these disaster stories, because it’s easily avoidable – just familiarize yourself with everything you’ll be using, or doing on race day.

Familiarize yourself with the climate and terrain you’ll be racing in, the gear you’ll be wearing, and the hydration and fuel strategies you’ll be using on race day.

Training for 3-hour marathon pace

In terms of actual training, there are a few different session types that are fairly critical. It will be close to impossible to achieve a 3-hour marathon pace by simply doing long slow runs all the time. Don’t get me wrong, you need to do those too, just not all the time. Vital session types are –

  • Intervals
  • Hills
  • Threshold
  • Long runs

Long Runs

These are pretty much a necessity when training for any marathon. They enable your legs and body to handle and, adapt to the stress and fatigue of running 26 miles. They also serve as reassurance in your mind, by having come close to the full distance before the actual race.

Your long runs should max out at around 18 – 20 miles. The thinking behind this is that once you start going over 3 hours for your runs, the negatives will start to outweigh any positive return. The negatives being increased muscle damage and longer recovery times.

When long runs are combined with sufficient weekly mileage, 20 miles will be more than enough.

It is also important to vary the pace of your longer runs. Don’t do each one at the same slow pace. I would recommend every second or third long run to be done with an increased effort. This will allow the body to adapt to pushing harder over a longer distance.

A harder effort means an increase in perceived effort of around 10 -15%. So, if your easy long run is at 50% effort, then you can push your harder effort to 60 – 65%.

Example long-run plan (one per week)-

  • 10 miles at 50%
  • 11 miles at 50 %
  • 10 miles at 65%
  • 12 miles at 50%
  • 13 miles at 50 %
  • 12 miles at 65 %
  • 14 miles at 50 %
  • 15 miles at 50 %
  • 14 miles at 65 %

Continue with this, or a similar schedule, until you are hitting 18 – 20 miles at 65% perceived effort.


To run a fast marathon you will almost certainly need to do some form of interval training. There’s also a great many opinions on the length, number, and speed of intervals that suit marathon training.

The bottom line is they will need to be a bit faster than a 3-hour marathon pace. How much faster will then determine the length of the interval, and how many reps and sets should be done.

For longer distance running such as this, I generally do 800 – 1600 meter intervals. With the shorter ones being faster than the longer ones.

Minimum target pace –

  • 1600m – 6 m 51 s
  • 800m – 3 m 25 s

That is your 3-hour marathon pace. Ideally though, towards the end of your training plan, you would need to be somewhere close to (or better than) this –

  • 1600m – 6 m 15 s
  • 800m – 3 m 00 s

You need to run faster than your intended race pace, to make that intended race pace feel more comfortable. This is very important. The first half or so of the race should feel comfortable.


When your legs are spent, and you’re running on the flat, the agony of then encountering a hill is like nothing else. It is one of the hardest mental challenges you will face. The desire to stop, or start walking, is almost irresistible. This is a situation you don’t want to encounter in your race.

Most races are going to have some hills. It is important that you train on some hilly terrain to account for this. Hard intervals on the track will do little to build your strength and speed going uphill. If you live and train in a mostly flat area, it becomes even more important to somehow incorporate hills into your training.

Hills present another challenge in terms of holding your target pace. It’s going to be difficult, if not impossible, to hold your desired pace going uphill. If you’re not prepared for this it can really throw you off during the race. And it’s not just as simple as compensating by screaming it on the downhill.

Going fast downhill is especially hard on your legs. If you do this early in the race you’re going to pay for it big time in the later stages. The best place to pull back any time lost from the uphill sections is mostly on the flat and a little on the downhill. This takes practice to pull off confidently.

I usually try to incorporate hills into my long easy runs to build extra endurance in the legs. I would say a hilly 18 miler is equivalent to at least a flat 20 miler. Also include hills once a week on shorter runs, where an emphasis is placed on pushing hard up the hill. These shorter hill runs will build your strength and speed uphill.

Threshold Runs

These are a particularly important ingredient in a fast marathon. They test, and push your ability to hold an uncomfortable pace for longer periods of time.

Performed at a lower effort than intervals, but harder than the ‘during the week’ runs. They should be performed somewhere between 75 – 85% effort. It is important not to push harder than this though, and overdo your effort. It must be controlled and shouldn’t be all out.

Ideally, you want to be doing these as one single continuous effort, with perhaps a mile left on either side for a warm-up and cool down. However, failing that you may split the session into 2 – 3 blocks with recovery between each of the blocks.

Example 8 mile Threshold Run

  • 1st mile to warm-up
  • miles 2 – 7 at 75%
  • or miles 2 – 2.75 @ 80%, 0.5 mile recover, miles 3.25 -7 @ 80%
  • 8th mile to cool down

Rest and Recovery

This is as important an aspect of marathon training as everything else mentioned here so far. If you don’t rest and recover correctly, you put all the other stuff at risk. It is easy to neglect this aspect and seriously hamper how effective your training can be.

The further into your training you get, the higher your mileage will become, and the more your body will demand rest and recovery. All the actual gains and improvements to your fitness are made while your body is at rest.

It’s crucial to get the best nutrition to maximize the recovery process. Your body needs carbs to refuel depleted energy stores. It also needs proteins to repair damaged muscle fibers from the previous session. This is when the muscles adapt and become stronger, in response to the extra load that was previously placed on them.

This doesn’t mean you can get away with chicken and bread for every meal! You’ll also need to ensure you get plenty of vitamins and minerals in the form of fresh fruit and veg. Keep your diet as healthy and unprocessed as possible. This gives your body the best chance to recover as quickly, and effectively as possible.

On top of adequate nutrition to fuel your recovery, you also need to get as much actual rest as possible, to allow that recovery to take place. It is important to get as much sleep as possible. As a parent of two young children though, I know how hard this can be. Just try your best to get as much as possible. Remember, that extra hour of Netflix in the evening isn’t going to contribute to your 3-hour marathon pace ambition.

Total Body Conditioning

In addition to your legs, it’s important to keep your upper body and core, strong and in good shape. I have always incorporated strength training and stretching into my endurance training. I do short strength sessions of 30 – 60 mins once or twice a week.

I always do a quick warm-up then stretch before running, and a longer stretch session after. It’s important to do this as muscles will be tight after long runs in particular.

Strength training can be bodyweight-type exercises like squats, pull-ups, chin-ups, press-ups, sit-ups, and crunches. Lightly weighted strength exercises are fine too. A good mix of these done weekly will ensure good overall body strength.

Towards the end of a race, form has a tendency to begin falling apart. Running with poor form requires greater effort, than running at the same pace with good form. Having a strong core, and upper body, will limit the losses resulting from poor form.

In Summary

So, this has turned into a pretty lengthy guide on the key things you should know about succeeding in a 3-hour marathon pace goal.

What’s evident is that everything mentioned above is important. The more of these key ingredients you can implement successfully, the higher you’re chance of success. Leave any one of them out at your own peril.

If I had to reiterate one point it would be this – try everything before race day! I can’t stress enough the importance of this one. Too many people leave so much to chance, and all their hard work at risk by forgetting, or indeed ignoring this.

Also, remember about positive thinking and mental strength, never doubt you can achieve your goal. Get your mind right and your body will follow.

I really hope this guide will help, in some way, to achieve your sub 3-hour goal. If it does then please let me know by posting a comment. I’d love to hear about you’re experiences, or indeed any advice you may have.


Always consult your GP before undertaking any form of weight loss, fitness or exercise.

Michael Duffy
Michael Duffy

Fitness, health, and outdoor enthusiast! 2 decade of experience training for, and competing in different sports. Boxer, runner, road cyclist, triathlete, and XC mountain biker. More about me here.

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