Running Nutrition And Supplements- What To Eat On Your Race Day

I was once asked by someone whether we stop and eat lunch during ultra-distance running of 56 miles/90km. I obviously laughed at first but later I realized that this was a genuine question considering that for that distance some runners finish over 12 hrs.

My experience over the years has taught me that matter nutrition and supplements are by in large a personal choice. What you eat and when is really determined by many factors including health-related conditions, in my personal case suffering from IBS ( Irritable Bowel Syndrom), there are certain foods that I can’t eat immediately before and during the race.

Fuel Management

The issue of managing your race fuel starts at training, and at best from a good eating habit lifestyle.  If you have developed a discipline of “clean” eating habits, you will find it easy to manage your fuel intake during the race. It is very much important to know what works for you.

The week leading up to the race is so critical, you have the challenge to balance your race tapering and fuel intake. If you obsess with weight like me you will have difficulties because 3 months prior to the race you might have dropped weight to your “ideal race weight” only to pick up few kilograms on the last two weeks before the race as you eat more than you work out. But the goal is to run efficiently, so the weight management suffers.

There are common nutritional needs for every runner that must be met, somehow, before a race is resumed.


Your main fuel source is carbohydrates and fat, the body stores the former and reproduces it as glycogen which is critical for your sustenance during the long run. The fat, on the other hand, is as important but is about 15% less efficient than carbohydrates as energy sources. The energy in the body is stored as glycogen in the liver and muscles.

It is important to note that the glycogen stores get depleted after 60-90 min of exercise and this is the ideal time to replenish and top up. What it means is that you want to fuel up around these times but others like to use distance, for example at every 9km I will replenish using either race food or using my favorite  Cytomax Tangy Orange Sports Performance Mix  

You can also take potatoes, bananas, mageu and sports drink of your choice.

Electrolytes imbalances

This happens as a result of sweating but there are also other factors including certain medications that might exacerbate it. So, if you are on meds it could be advisable to check with your doctor.

Fluids and electrolytes are essential to the body to produce energy and contracting muscles.  A person loses 1litre of water for every kg of weight they lose, and as a rule of thumb, a person needs to replace 500ml to 750 ml per hour.

So there is an issue here of over-hydration when runners stop at every aid station to have water, I am not mentioning the time wasted during the process. Here I discussed the amount of time wasted on water point station Ultra Marathon Training Guide-Comrades Marathon Training Tips

Magnesium and sodium are the two most important electrolytes that are critical for any endurance sport. There are many products out there which provides a good amount of these, magnesium is good for the conversion of glycogen to glucose, and therefore important for the provision of energy. It is important for protein metabolism, which is vital for strength and power and lastly for muscle recovery, which prevents cramping and fatigue.


One of the most difficult things which we struggle with as runners are getting a good balance of hydration such that we neither dehydrate nor overhydrate. There are many factors that can contribute to finding oneself on either side of the extreme.

Naturally, during endurance exercise, we lose both water and electrolytes ( sodium and magnesium). The challenge is to know which one to replenish at what point, at the time you would think you need water whereas you need electrolytes.

I must say knowing which one to take at a given point comes a lot through practice. If you are a careful athlete, you will be able to study your body in different weather conditions and be able to work out when to drink what. I emphasize this with my runners that each person must train and understand their body’s needs as they train so that come race day they are not overwhelmed with water stations at every 3k.

I sometimes see runners eating a watermelon and immediately drinking water, that’s too much water already, as a matter of fact, I would rather eat watermelon more and drink less water if any because in there you have enough water to sustain you from one point to the other.

It is recommended that you start your race adequately hydrated, as a personal preference,  I drink 1 lt of water at least an hour before the race, and sip between 300ml and 500ml of my electrolytes. In this way I avoid aid stations for about an hour or so, better still, as I carry my electrolytes with me I am able to maintain the discipline of not overhydrating myself.

Over-hydration, water intoxication or water poisoning

 During running we lose water and electrolytes mainly sodium (salt) and magnesium. Athletes tend to correct water loss and forget to correct the electrolytes, which leads to low sodium levels in the body (hypernatremia). At worst water poisoning during endurance exercise can be deadly.

Overhydration will cause your legs to be sluggish and running becomes more difficult, you may even start cramping and wonder why because you think you have had enough to drink, no you had too much water which flashed out sodium and magnesium that are supposed to protect you against cramping.

The best way to avoid this situation is to balance your water intake with your electrolytes, do this during your training, find the best method for you and take that to your race.

Always carry a rehydration solution with electrolytes for long runs and any race longer than 15km.  Drink when you are thirsty not in anticipation of being thirsty. Avoid alcohol the day before the race (alcohol causes dehydration)

Last Mile

Plan your nutrition intake, know what to eat the night before the race and a pre-race meal. I love my oats meal and coffee. Get yourself hydrated in a week leading to the race, as a personal rule I drink 4lt of water per day because of high-intensity workouts I do, so I don’t change this at any point.

Don’t stop at any and every aid station, but when it’s hot don’t forget to spray your body with water from the head down to keep it cool.

I would love to hear from you what you think about this article, is there something that you think I missed? What works for you when it comes to this subject. Please leave your comments on the relevant section below and also note that your email address is not shared with anyone. Looking forward to hearing from you.

31 thoughts on “Running Nutrition And Supplements- What To Eat On Your Race Day”

  1. This article is GREAT for me because right now I’m training to run a marathon so it’ll be very important what I eat, of course, it probably isn’t as important as if you run 90 kilometers, but I still think that 42 is a pretty long way. I’m really glad for this article and it’ll help me a lot, thanks.

  2. I really enjoyed reading through your article. I never knew that magnesium and sodium were responsible for endurance in long distant races and thus need to be replenished in as much as water and other nutrients are replenished. Thanks also for reminding us that every athlete should pay attention to his body at all time to know what’s needed at every point. Thanks so much

  3. This is a very good post.  A really informative read on the topic of running nutrition and supplements that runners need on a race day.  I’ve actually learned quite a bit.  For instance i did not know that the bodies store of Glycogen tends to get depleted after 60 – 90 minutes of exercise.  

    There is one question that i have for you though.  You mentioned race food and i have no idea what that is so my question is. What exactly is race food?

    1. Hi Donald, race food is like a chocolate bar packed with good nutrition for endurance exercise.

      Thank you for taking time to read

  4. Thank you for your post. It is useful for me. I plan to join this year Marathon in New York city. Right now, I try to some long distance runs. I often suffer from pain and cramp by the end of my run. I don’t know why and think about having research on this, but never take time to do.

    Here comes your article. I like your description on over-hydration, water intoxication or water poisoning. I bring only water with me during my practice. It is apparently that I have too much water which flashed out sodium and magnesium or other precious nutrients. This is why I often have cramp in the end of my practice.

    You are absolutely right that I am going to take hydration solution with electrolytes in my practice. I am so happy that you help me sorting out my problem.

  5. I wish I had this information when I ran the Paris marathon back in 2012. It was one I struggled to finish mainly because I didnt replenish electrolytes (retrospective vision is always 20/20!). Eventually I did finish (it took me over 6 hours) but I was in a great deal of pain. I vowed that next time a run a marathon, I would be better prepared on the day! Thanks for an excellent article – well researched and a great read.


    1. Sandeep, it is my pleasure, thanks, I hope you are now doing better. It is my dream to run Paris marathon, maybe next year I will

  6. Working out is one thing, but in my opinion, what really separates the amateur from the professional is that the professional puts in the extra hours of experimenting with different foods and methods to fine-tune his own personal way giving him the edge. Basically he has the experience and knows what works and doesn’t.

    You said you prefer drinking coffee at your pre-race meal.  Is there a specific reason for that (caffeine?), or is it just because you like coffee?

    1. Hi Faheem, as you would imagine there are many theories about what coffee does good and bad, I found it to be a booster for me, I will take it without milk though.

  7. Balancing a runners diet is  very  important and  necessary. A disciplined  runner needs good eating habit and also, a clean eating habit is  not  excluded. Taking alot of  water and  fruits that contains  water is also very helpful as  their running will cause them to loose many water from their body. One  of  their everyday and compulsory meal is Glycogen which is carbohydrates and fats which help in maintaing and building their body  balance. 

    And my question is, 

    Maintaining body balance, does  it  apply to both gender irrespective of the nature of ones body? 

  8. Being a personal trainer previous to what I do now, completely agree with everything you’ve written in here. A 12-hour marathon is quite a bit, I would be wondering about lunch in between as well.

    Hydration is of alternate importance when getting ready for anything that’s going to require keeping up endurance. My daughter plays rugby I usually tell her to hydrate a couple of days before she has again. Last time she didn’t listen to me and ended up with cramps, hopefully, she’s learned how important hydration is.

    I enjoyed reading this article as it just touches upon what I’ve learned from my personal training base.

  9. My first marathon will take place in a week’s time. It’s my first 10K so I’ve been training really hard but after reading this, I realized I may have overlooked some nutritional aspect to keep my body at an optimum level. Water is my go-to source for hydration and I must say, I don’t often take electrolytes because of the taste. After training, I always drink a lot of water and although I feel weak on the legs, I thought it was just the exercise. 

    Do you have any recommendations for rehydration solutions that has a more natural taste? Thank you. 

    1. Hi Cathy, there are few in the market that I know, USN does have quite a few but my preference is Cytomax. If you don’t mind me correcting you on running terminology, a marathon is 42k, half marathon 21k, ultra-marathon is anything from 48k and above and anything less than 21k is called a race.

      Thank you so much for your comments

  10. I’m a fitness specialist but, I’ve never run a marathon.  While I know how important it is to listen to your body before, during and after workouts I feel like my marathon runner friends have a hard time finding that balance at times more than I do.  I have such respect for anyone running at that level but, like you said it’s really subjective what we should or, shouldn’t be eating.

    That said though, you cover all the 5 elements I always speak to when checking in with runners.  I loved the advice about spraying yourself down top to bottom with water.  That’s what I do when I know I’m at maximum water intake capacity.  I drink water like it’s my job so my body will always know when I’m at maximum capacity.

    I do have a question for you when you described your night before a marathon meal you included coffee.  That doesn’t affect your sleep at all?  Just curious because I’m so sensitive to it I can’t have it after 4PM.

    1. Thank you for your comprehensive comments, I am a coffee addict, I can drink it at 12 mid-night and fall asleep immediately, so for me it’s not a problem but I know that most people have problems with it.

  11. Preparing for my 2 Oceans and then comrades 2020. The article helps a lot especially when it comes to cramps, I cramp a lot, wasting 20-25min at recovery station then boom I’m recovered to complete the race. So I want to improve my time & stay cramp-free.

    Share more ideas on how to deal with cramps, please? Thanks for the information

    1. Thank you for taking the time to read my article, I think there are three things you should look at if you want to deal with cramps effectively, in this particular order

      1. You need to warm up about 10 mins and light stretch before your workout and most importantly about 15 mins after the workout, if you are doing a race, use the first 10 mins from the start to warm up before getting into your planned marathon pace
      2. Take a sports massage every second week, to decrease muscles spasms and tension
      3. Use electrolytes supplements which have hydration sources and is good for pre-during-and post-workout. There are other good products from USN, their rehydrate is also good.

  12. In Addition:

    1. With regards to Hydration/Alcohol:
    Exercising soon after drinking alcohol can make this dehydration worse because you sweat as your body temperature rises. … “Hydration also helps control your body temperature so you’re more likely to overheat if you’ve been drinking alcohol.” Secondly, alcohol interferes with the way your body makes energy.

    Thank you DD for your articles, I hope and wish that manyof our fellow Runners will take advantage of your FB page.

    1. That’s right Priscilla but some runners love their alcohol, they call it carbo-loading and recovery drinks after the run. At the end of the day, I always say check what is the right thing to do and decide what you are going to do thereafter.

      Many thanks for your inputs, much appreciated

  13. This article is very informative.I always struggle with cramps during marathons & ultramarathons.This affects my performance so badly. I’ll try and test a few products,because obviously the ones I’m using now are not working and it’s really frustrating.

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