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Your Perfect Marathon Nutrition: All You Need To Know

Nutrition is training! Eating healthy food is one of the most fundamental ways we can interact with our environment – so let’s make the right choices!

People regularly have questions about their nutrition plan; what to do during training, in the build-up to a race, during and after. It’s not surprising, countless of textbooks are filled on this. Human bodies are complex, with all of our unique quirks and preferences on top of the huge number of things that impact upon our bodies every day – each of us will have our own needs.

This guide is designed to equip you with the tools and knowledge you need to be confident in your own nutrition plan. And yes, of course, we’ll provide a template that works for most people too!

Your training, nutrition, and recovery are the three pillars that will predict your race day performance. So, let’s talk nutrition!

The Fuel

There’s been lots of talk in recent years about fat burning, keto adaptation and other fringe nutrition strategies; they’re interesting but do not improve race results or lab testing and are notoriously difficult to maintain for long periods.

Also, even if you train using one of these strategies I strongly recommend you still rely on carbohydrates for race day and the build-up week.

So, we’re fuelling our muscles with carbohydrates.

You only need to know three things (1) what to do in the days before the race, (2) what to eat on race morning, and (3) what to eat and drink during the race to get your personal best.

You might think this is oversimplification but if you can get this right you’ll be ahead of the vast majority. Every training session is a chance to practice what you’re going to eat for the big day. That means working out what you’ll need to eat on race day and a bit of experimentation to find out what works best for you.

Good to Knows

What’s the course like? For instance, is there a big hill where you’ll find it harder to eat so you should take in food before and after?

What nutrition will be provided on course at the aid stations and what distance will you cover between them?? If you can find out then you can practice with it. If you know ahead of time that you don’t tolerate it then you can plan to carry more of your own choice fuel.

What about the weather? Will it be hot or cold?  Your finishing time and calories expended will increase with significant heat or cold, particularly if you are not used to it. You might plan to carry more food.

Train Your Gut

How do I train my gut?

Research is increasingly clear that carbohydrate intake is linked to better performance in what is called a ‘dose-response relationship‘. That means more carbs yield a better finishing result. But if you try to eat 2-3 energy bars every hour on race day without practicing, you risk putting your gut under stress and finding yourself in an embarrassing situation!

You spend so much time training your muscles, heart and lungs; when you also include your gut in the training programme you will perform better and reduce the risk of a GI problem that could end your race early.

How do I train my Gut?

Just as with your muscles, your gut can be prepared to handle what a marathon will throw at it. Start getting used to your race nutrition plan by practicing it in training as soon as your marathon training plan starts. That means eating as though it’s race day in all of your key sessions.

If you know what nutrition products will be given out at the race then you can try that, but many runners prefer to stick with what they know and trust.

We advise athletes do cyclical training of your GI systems just like with regular training plans – sometimes you back off, other times you really work at it.

Eating on Easy Days

On easier days when training is not focused on building speed or distance, feel free to experiment.

Some runners like to see how they can handle fat as a fuel source by reducing carbs during those sessions or running before breakfast. Your speed in these runs will be slow. The hope is these “fasted” runs will allow you to develop your ability to burn fat.

Why is that good? You’ll delay hitting the wall, and if you do hit it you’ll be able to maintain a faster pace. There’s also evidence that these training sessions boost other aspects of your endurance training.

Eating on Harder Days

On hard days when you train fast or work on your long runs, quality of the training is important. This is the perfect chance to train your gut to perform just like you will on race day.

These are the days we try to work toward 60+ grams of carb per hour for sessions over 90mins. That’s approximately 1 YPB During bar every 25-30 minutes. For even longer sessions over 2.5 hours you might aim for as high as 80-90g/hour.

Some elite marathon runners will consume 75+grams of carb per hour. Look at the likes of the Tour de France carb intake.

Tip: You can only absorb more than 60g/hour of carb with a mix of carbs. With pure glucose, you max at 60g/hr. Check to see if your nutrition products have a mix of glucose and fructose like you will find in natural products like YPB bars.  

You may not be able to tolerate that volume straight away, but your GI system will learn to deal with it over time. This is just like building up your long run. This is how elite level athletes can consume such large volumes of in races like the Tour de France – they had to work on it just like the rest of us.

Upset Stomach?

Each athlete has to work out that balance between GI comfort and the maximum amount of carbohydrate you can ingest. We all know those lucky people with iron stomachs, however some of us have a low threshold for stomach cramps.

Tip: Be flexible with your nutrition plan. If you feel like food and drink is pooling in your stomach, ease off the intensity and stop eating to allow your gut to catch up before hitting the gas again.

Carbohydrate Sources

Fuel Your Personal Best

Where can you get the fuel you need?

Among most brands: 1 bar = 1.5 gels = 5/6 chews

  • 1 Banana 24-30 g
  • 1 Gel   21-27 g
  • Energy bar 20-40 g
  • YPB During bar 27 g
  • 4-5 Chews 16-25 g
  • 500 mls of sports drink = 35 g

Can’t I just Eat When I’m Hungry?

Unlike fluid absorption, you will burn carbs faster than you can absorb them. If you wait till you’re starting to feel hungry or tired then your long run or race will have a bitter and shuffling end!

Early on, your gut is in prime condition to absorb carbs. Later in the race your stomach could refuse to take anything in. So, start eating from early in the run so you can finish strong.

Disregard this extremely well studied approach and your legs will let you know! This is one of the most common nutrition errors seen again and again in marathoners, ironman triathletes, and ultra-distance racers among other events. We also know that those who get it right finish fastest.


It’s a simple concept, you eat more carb-rich foods so that your muscles soak it up like a sponge giving you a fuel meter that’s fuller than it’s ever been!

This doesn’t mean overeating, just prioritize carbs before salad and protein etc. Don’t leave this till the last meal the day before, you might still feel a heavy stomach in the morning and risk an upset stomach on the course.

Even though this should be a fun part of endurance races, research consistently shows that runners enter race morning with muscles that could have absorbed more carb. Carb-loading is a part of your race! Want to finish strong and avoid hitting the wall? Carb-load!

There’s no need to follow a complicated strategy for this – all the old strategies are equal in the lab. What’s important is that for about 3 days before the race you prioritize carbs in each meal and you aim for 10-13g/kg/day. Sample plans below.

If you’re travelling to your race, look up restaurants and menus before you get there. Many a race has been sabotaged by miles of wandering for a pasta place the night before a marathon!

Sample Meal Plan For the Day Before

Breakfast: a  bowl of porridge topped with a banana, wholegrain toast or a bagel and a glass of orange juice

Lunch: a jacket potato and beans with salad

Dinner: a  pasta starter, a chicken and vegetable main with brown rice, fruit salad and low-fat yoghurt

Snacks: bananas, crispbread, a handful of dried fruit, rice cakes

Breakfast Before Your Long Run / Race

Know your hydration

This is down to personal preferences but it should be about 150grams of carbohydrate with little fibre. Whatever you’re used to eating before your long runs is probably what you should go for on race day. If you’re travelling to the race, pack your breakfast too.

Aim for breakfast about 3-4 hours before the start and remember to get about 500mls of fluids in the 2 hours beforehand. Your urine should be pale, if it’s not then hydrate more before the run.

Need Your Coffee?

Caffeine and exercise performance has been a hot topic for decades. Does it help? Short answer, yes but not for everyone and side effects may not be worth it for some. About 3mg/kg (around 200mg for the average person) is enough for performance benefits.

If you like coffee then a double espresso an hour before the race is about right for peak absorption. If you hate coffee then most caffeinated gels contain between 25-50mg of caffeine – you can take these in during the race for ongoing benefit.

Do NOT exceed 400mg of caffeine in a day.

Waiting for the Start

The hour before the race starts is usually when you see people anxiously bouncing on their toes, queuing for the toilet, trying to stay out of the wind/rain, or when us mortals watch the lean and sinewy runners warming up with some strides in tiny singlets!

During all this, you should be sipping about 200mls of fluids, and about 20 minutes before the start try to get another 20-25 grams of carbs (in your drink, gel, bar etc.).

During the Long Run / Race

Let’s keep this easy: drink to thirst and eat what you ate during your specific race pace long runs. Easy!

If you don’t remember what that was then aim for about 1 typical sports bar every 30 minutes or 1 gel every 20 minutes.

Thirsty? Drink. Don’t overthink this or drink too much; if you’re not thirsty then you don’t need it. Humans have been doing this for a long time, thirst is a great indicator and will adjust with temperature, sweat rate etc.

How Much Carbohydrate Per Hour During Your Long Run / Marathon

What should I eat during my marathon?

After the Long Run / Marathon

If you just finished the marathon then relax and indulge! Then follow a reverse taper over the next 2-3 weeks.

If you just finished a long run then you need to refuel carbs and take in about 20-25g of protein immediately and again after 3 hours. Your protein can be a recovery bar, shake, two scrambled eggs, whatever you like. If you’re planning on running again in the next 24-36 hours then carbs are a priority and you need to eat within 30 minutes of finishing your run. Aim for about 100g of carbs.

Why Plan My Nutrition?

Here’s a quick thought experiment for you – how many hours do you think you’ve spent preparing for a marathon by race day?

Say it’s an average of 3-4 hours per week over 12-16 weeks, typical for a 3-5 hour finishing time. That’s somewhere around 50 hours of running! Yet how much time do any of us give to preparing or planning our training and race nutrition? If you’re like most athletes I’ve asked, it ranges from no preparation at all to maybe asking a friend who’s done a marathon for a few tips.

If you can spare 10 minutes to read this guide and another 10 minutes each week to plan out your training nutrition for each session, then you can nail your marathon!

If you want to make this even easier, you can subscribe to YPB for personalized nutrition packages sent to your door.


  • Train with your race nutrition plan every chance you get! Your goal is to be able to tolerate 60+ grams of carbohydrate per hour at race intensity.
  • Practice your breakfast plan before your long run. Find out what works for you.
  • Look at the course route map and the nutrition at aid stations; know what’s available so you can practice with it.
  • Plan your dinner the night before at a place that you know is good. Don’t wait till the last moment.
  • Have all your race nutrition purchased and counted, don’t wait for the race expo.

3 Days To Go

  • Carbo-loading begins: replace protein and salads in your meals with carb-rich foods.
  • If you have a sensitive stomach, reduce fibre intake with 48 hours to go.


  • Same as you had on long run days, eat 3-4 hours before the scheduled race start.
  • Aim for about 150 grams of carbohydrate.
  • Is your urine pale? Drink 200-500mls of fluid in the 2 hours before race start depending.

1 Hour To Go

  • Your race nutrition is almost finished if you’ve carb-loaded and had a good breakfast
  • Now, get a gel/bar/sports drink in with about 20-30 mins to go

During the Run

  • This is the easy bit – do what you’ve practiced, whether that’s 30g of carb per hour for a runner following a slower and more relaxed intensity or 60+g/hour for the elites at high intensity.
  • If you feel bloated, ease off the pace and stop eating and drinking until you start to settle then gradually get back on pace and plan
  • Aim for 30-60 grams of carbs per hour.
  • Drink to thirst unless you have worked out sweats rates and have a practiced hydration plan.


We hope this helps with your training and race day! Remember – nutrition IS training!

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Ultra Endurance Events: What’s going on in my body and my mind?

Have you completed an ultra-distance event or thinking of doing one? An Ironman? An ultra-marathon? A 24 or 48-hour event? All these events challenge the body far beyond what is experienced even during a tough marathon.

No time to read? Here’s the cheat sheet!

One of my Ultra Low Points!

I’ve had lots of highs and lows in racing. But not many when I’ve captured the low in a photo! A couple of years ago my wife and I ran the TransRockies Run – a 6 day mountain run event. The distances are relatively modest however once you add in the sleep deprivation experienced at altitude, notably we live at sea level, and the elevation changes in this event which dwarf our local hill training – suffice to say we had a tough race!

Battling the fatigue

We experienced significant altitude sickness, heat by day, freezing during the night, we had rubbish sleeping bags, so that by day 4 our bodies were ruined – see the picture of me? That’s me trying to get my head ready to eat some pancakes and run again!

But like many of you, still we continue and we go back to do longer and more challenging events! 

They’re tough, a major physical and mental challenge. But the challenge is what we’re here for!  Ultra distance events don’t have the same limiters as shorter all-out events. In a sprint, you’ll know what you’re finishing time is likely to be within a small margin. In an ultra, you can have a great day, or finish hours off your pace, or not finish at all – even if you’re the best in the world.

Ultra distance events are a chance for us to explore our depths. They offer a positive environment to answer the questions:

Can I do this,? What will happen when I start hurting? How am I going to respond when the suffering mounts? Do I have the mental fortitude to endure when all the signals from my body are begging me to stop?

So what are some of those signals? What exactly happens to us during these events? Let me take you through a whirlwind tour of the havoc wrought in your body by an ultra-distance event!

In this post we’re not going to talk about the months and years of training required; we’re going to show you some of the changes that take place in your muscles, organs, blood, and also your mind during ultra races.  

How can we tell?

During really long or very tough exercise, the cells in your body become leaky and let stuff pass through their walls more easily – their permeability increases, changing a solid barrier into a sieve.

So, chemicals, proteins and other substances that should be on one side of the cell wall move to the other side. That gets worse the harder or longer you exercise; that means we can measure those substances and see what’s going on at the level of your cells. Pretty cool!

Main Point: Your cells become leakier as you exercise harder and longer. We can measure levels of various substances and metabolites in your blood to get an indication of the amount of damage taking place inside those hard-working cells of yours!

The Good News

All the worrying things you’re about to read are temporary! Well, nearly all of them – we’ll cover the effect of years of endurance training on your heart muscle in an upcoming post.

The changes we’ve mapped out below will help to explain why you feel so awful during these races, just like I did in that photo!

First, Muscle Damage

Hardworking muscles that are damaged by exercise leak specific enzymes into your blood. Some of those enzymes can go up by hundreds of times their normal levels (like creatine kinase and myoglobin). The levels are scarily high at the end of a 48-hour ultramarathon!  

Running for that long causes severe muscle damage! This is mind over muscle!

Muscle Strength

After ultramarathons, particularly mountain races where there is a lot of climbing and descent you probably felt weak as a kitten the next day, right? So, how long does that last after, say a 100-mile mountain run?

Well, you may be surprised – most of your strength is back after just over 1 week but it takes another week for your muscle function to normalize. So that’s 2 weeks for the connection between your muscles and nerves to recover.

Namely, your neuromuscular function takes longer than your muscle alone to settle down. Neuromuscular function is the name given to how your nerves and muscles work together to make you move. Your brain recruits muscle fibres by making your nerves send little electrical impulses into the muscle – the more muscle you recruit at the same time, the harder you push. It takes 2 weeks for that nerve-muscle link to bounce back to pre-race function.

So that’s why the stairs are a struggle for so long after an ultra!

Heart, Liver and Kidneys Damage

These are some hardworking organs – and you’re about to push them through a massive challenge.


Wait! My liver isn’t doing any running, what’s going on there? Your liver sits in the upper right of your abdomen and it’s basically a very complex filter. It changes chemicals from one type to another. It gets first dibs on anything that comes into your bloodstream from your stomach to detoxify and make it safe for the rest of your body. Your liver also helps in metabolism, glycogen (carb) production, and hormone production among many other jobs.

Because of all these critical functions, a healthy liver is vital for athletic performance and recovery. So when you run an ultramarathon, you’re giving your liver a workout too.

We can easily test the three most important markers of liver damage in your blood; the same as those we use for annual health screening and for monitoring liver disease from any cause.

You’d expect to see these double after a tough weightlifting session. But after a 24-48 hour feat of human endurance these could be 20-30 times higher than normal levels. Those signs of liver damage will take about a week to settle down to near normal levels, though they’re back to 5-10 times normal levels after only 2 days. 

Tip: Don’t go for those health insurance blood tests the week after running an ultra marathon!


This one isn’t a stretch of the imagination. Your heart is a muscular organ, muscles suffer strain when they work hard. Beating hard and fast for an entire ultra-distance event is a major challenge for your heart, and it shows.

To look at this we can use the blood tests that we normally use to detect a heart attack or heart failure. Heart failure is usually a condition of old age when your heart can’t keep up with pumping blood around your body – that results in a buildup of fluid in the lungs, ankles, and around the body.

During ultra-events of 12 to 48 hours there’s a marked increase in heart strain biomarkers – up to ten times baseline levels!

Taken out of context, these results would be enough to diagnose heart failure or a heart attack in many athletes! Thankfully they go back to normal after a few days, which they would not do in a clinical heart problem. However, this repeated strain is what is blamed for the chronic scarring of the heart seen in lifelong marathon runners.


It will come as no surprise that your kidneys get stressed out during prolonged exercise. You’re probably thinking this only matters if you don’t drink enough fluids – don’t be so sure!

Like your liver, your kidneys also act as a complex filter but for different reasons. During ultra-exercise, the cells lining the part of your kidneys that filters blood get inflamed and damaged. This is like taking the dust filter out of your hoover – sure you hoover up some dust but a lot of it gets spewed back out again!

It takes a day or two for your kidneys to catch up on this filtering process. This is one of the reasons you should not use anti-inflammatory medications to mask injuries or pain. Those drugs put extra stress on your kidneys and can cause serious problems – I’ll explain this in more detail in a blog post very soon.

Oxidative Stress and DNA Damage

One of the by-products of our use of oxygen to make energy is the production of reactive oxygen species – call them ROS. These are forms of oxygen that can damage proteins and DNA in your body – oxidative stress. Stress is bad, and oxidative stress is often quoted as the reason we should all eat more antioxidants. That’s one of the main reasons why we use wholefood products at YPB, they contain the antioxidants you need while on the move (unlike refined energy products).

Yes, oxidative stress markers in your body will rise during ultra-distance events but… not very much, only a few percent. That’s because your body is an expert at fighting these on the go and increases the number of antioxidant substances in your body to balance.

However, even that small change causes measurable DNA damage in your white blood cells over the course of a marathon, and far more damage for longer events.

If the impact is small, why mention it? Well, this will blow your mind! Two studies found that higher levels of antioxidants in your body before starting an ultra-race is linked to faster finishing times.

So, get your diet in order and get your antioxidants up before your next ultra! Think of some of the greats like Scott Jurek or Rich Roll who eat plant-based diets. They’re blood is surging with antioxidants at the starting line!

My theory on this is that the effect is the same as you see with the experience of flow in athletes. The benefit isn’t the antioxidants on race day, rather the cumulative benefit seen over months and years of higher levels during training. The same with flow, people who enter flow states more frequently in training tend to finish faster regardless of how they feel during a race (flow blog to follow). 

If you want to know more about the science behind this, researchers use 8-hydroxydeoxyguanosine (8-OHdG), which is an oxidized/damaged part of DNA, to look for DNA damage. When your body repairs your DNA, it gets rid of 8-OHdG in your urine.

So, urinary 8-OHdG can be used to examine oxidative stress and has even been identified as a risk factor for cancer, heart disease and diabetes.

What if you do really long training sessions all the time?

Maybe you have a week-long stage race coming up and as well as everything else now you have to worry about damaging your DNA?!

Don’t worry, yes you will have some oxidative damage to your DNA and this increases with the duration of the race but, this actually goes back down while you consistently do long distances over consecutive days.

Your body appears to increase your antioxidant processing in response to this shock. Your immune cells release proteins called cytokines with a specific role to inhibit oxidation and reverse the widespread inflammation resulting from your determined run!

What else do we see from inflammation?

The number of your immune cells goes up and blood markers of inflammation rise considerably. Fortunately, these deranged results mostly return to normal after 2 days. It should be said, these are average levels taken across many people, within that group some people have extremely abnormal blood tests during an ultramarathon while others aren’t so bad.

Breathing hard?

All that persistent effort causes you to breath heavily for a really long time. Have you ever hyperventilated and felt tingly fingers or lips? That’s from exhaling too much carbon dioxide which raises your body’s pH which modifies blood electrolyte balance for a short time.

Well, breathing hard for 1-2 days of exercise does something similar but much more slowly – it causes carbon dioxide levels to drop in the blood, raising pH and dropping calcium while raising potassium. That low calcium can persist for a couple of days but it is only a slight drop.

You may be wondering about sodium levels in all this as that’s one of the big concerns endurance athletes have, especially in the heat; in all these groups of people, sodium didn’t change much. Abnormal sodium levels are almost always down to hydration problems, namely drinking way too much.

We can’t find a study that’s looked at specific signs of muscle damage for the muscles you use in breathing – it probably isn’t possible – but there are lots of studies showing improved endurance performance by training your respiratory muscles. After all, they’re just made of more muscle tissue that can be prepared to work more efficiently for longer.

Endotoxemia and Nausea

During a 100 mile ultramarathon, stomach symptoms are experienced by most runners at some stage, with nausea being the most common complaint.

We mentioned that your cells become more sieve-like during ultra-exercise, so they leak. Well, that means bugs and toxins can leak from your intestine into your blood – that’s called endotoxemia and it makes you feel sick. More toxins in your blood means more nausea. In one study on a 100-mile run; nutrition, hydration and temperature didn’t seem to have any role in causing nausea.

Psychological Stress and Perceived Recovery

There’s a part of your brain (pretty close to the front – your prefrontal gyrus) that’s heavily responsible for choosing one course of action over another. So when an inner voice says

  • Please stop, everything hurts and I hate this!

there’s another inner voice saying

  • Keep going, if I can just get to the next checkpoint… and the next…

This little heroic part of your brain is what lets you pick the harder option. That’s true in every part of your day (fruit over chocolate etc.), but it gets tired. An ultra-marathon is a microcosm if this in an extreme setting.

In fact, ultra runners who are better and more flexible at directing their attention and concentration in this way while ignoring irrelevant information tend to finish races faster than those who struggle with it.  

Why bring this up?

Well, if you spend 100-miles or 24 hours or a full Ironman continuously choosing to keep going over stopping for tea and cake, that is mentally exhausting and comes at a cost. We know what that cost is! Would you like to know? This might be useful to explain to your significant other before your next ultra!

Here are some of things you’re likely to feel after a typical 24-hour ultra (shorter races have this too, just less intense).

  • General stress
  • Emotional ups and downs – anxiety, anger, irritability
  • Social irritation – you’re more likely to get upset or pick a fight over something small
  • Rumination – have you ever spent days after a race just thinking about that one thing you could have done better?!
  • Fatigue and low energy – difficult to concentrate and get things done, difficult to make decisions or motivate yourself
  • Burnout – this is when you’re more likely to feel like quitting, it’s offset by having a good race but if you’ve had a DNF you’ve probably also had that thought of “I’m never doing this nonsense again!”
  • Sleep – disturbed by frequent waking
  • Physical – injury, peculiar bodily sensations

I’m writing this list smiling at how scarily true it’s been for me after lots of races!

But how long does it take for your mental state and sleep to recover? Simple –

  • 1 week for most of your negative stress reactions to go back to your baseline
  • but 2 weeks for your positive mindset (motivation, energy, enthusiasm) to recover to pre-race levels

Why is this so important? Well as you saw above, many of your blood tests recover more quickly that your mindset.

Regardless of these results, most ultra distance racers and coaches state that it takes closer to 5 weeks of recovery before you’re ready to go back to regular training.

Your sense of how you are feeling is more sensitive than any tests we have to detect over-reaching – over-reaching is the term given to pushing yourself too hard for too long that results in a bad mental state and poor exercise performance.

If you really want to monitor your mental state before and after your next ultra, just take the RESTQ-sport questionnaire. If you do, let me know what happens!

This is useful because ignoring how you’re feeling is one of the most common causes of overtraining. Injury and fatigue should be tracked just like distance and pace – these are the early warning signs for overtraining.

In fact, a lot of the research in this area comes from military sources. They want to know how hard they can push their recruits without breaking them. If you want to train with ‘military precision’ then maybe give some kind of simple mood and stress tracking a go!

Main Point: During training, just like after your next ultra-marathon, listen to how you feel to judge when you should return to regular training. Do you feel like training? Are the legs still heavy? How’s your motivation? Still feeling tired or are you eager to get out? 

Congratulations! Despite all that ultra damage, you’ve come through it!

Have you been through this experience? Did any of this come as a surprise? Let us know your experience in the comments below!



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