Ask the Experts: Marathon Nutrition Q+A with Ruth McKean

Hi everyone

ASICS Super Six dietician and ASICS PRO Team member Ruth McKean will be online between 1pm and 2pm today to answer queries about marathon nutrition.

Ruth is a leading sports dietician and a member of the British Dietetic Association and Health Professional Council. She is also an advisor to the Scottish Institute of Sport, specialising in helping athletes of all levels prepare nutritionally for competition. She is also a former Scottish National 5,000m champion!

If you're wondering what to eat and when in training or racing, Ruth's got the answers. 

We're opening the discussion now so Ruth will be able to get stuck in straight away at 1pm (rather than having to deal with too many questions all at once). That's enough from me - time to get posting!



  • Thanks Alice,

        I have a question for Ruth... I have been on a rather big weight loss journey - having lost just over 10 stone in the last year and a half and am happy to say I am now at my target weight or just over nine and a half stone (I'm 5" 6).

    I now run between 30 and 40 miles a week and cross train with weights and a resistance band on my running rest days.

    What I would like to do now is reduce my body fat percentage and increase my muscle mass (preferably without changing my present weight). I'm a vegetarian and am unsure what I should be eating to achieve this.

    Any advice would be greafully recieved.


  • Hi - I have a question about running and eating. I have completed 6 full marathons and really struggle to refuel on the run. I have tried and given up on gels and bars as they give me terrible stomach cramps. In fact, I have even given up on banana. I just don't seem to be able to take food on board. I run marathons and training on water alone and am pretty sure that my times would be better if I could learn to take on food.

    How can I train my stomach to accept food?

    Thanks - any advice you can give will be much appreciated.

  • Hi Ruth,

    I'm training for London but I've got a few stag dos coming up that I really can't avoid. Rather than do the sensible/strong option and refrain from too much alcohol, do you have any tips for low-calorie boozing?

  • Hi Ruth

    I have a question about hydration rather than nutrition if that's ok? The two marathons I have completed have both resulted in me producing extremely dark brown wee which is obviously a sign of pretty bad dehydration.

    I have felt well after both marathons and within a few hours my urine colour gradually lightens to normal. I have only one functioning kidney. I drank quite a lot in the marathons and was very surprised that I was in such poor shape hydration wise.

    Is it just a case of trying to drink MORE or am I better trying to increase the energy drinks? I can probably only stomach one bottle throughout the whole race before I feel sick?

    And should I be concerned that I am dehydrating so much if the level improves on its own with no intervention?


  • I need some advice on how to make sure I'm eating enough to fuel my training because I just get so confused with all the different things I read. How much is enough? Thanks
  • I struggle to use gels during my long runs (just dont like the taste or texture), so have been trying out shotbloks for my last 2 marathons.

     During LSRs I have been taking one 'blok' per mile from mile 4 onwards which seems to work, but yet on race day this strategy doesnt seem to work well for me and I end up with uncomfortable bloated stomach and nausea. This in turn affects my running performance.

     Any suggestions what I can do differently to make race day a more pleasant experience?


  • why is it throughout my long runs i crave everything from a curry to a cholcolate bar but when i get home all i can stomach is a glass of milk and malted biscuits??? 
  • Hello Ruth,
    this is slightly more general.  I'm thinking about cutting out types of food (probably starting with bread) to see if this makes me less gassy.  How long will I need to leave it before I might expect to see a change and what sort of things can I replace it with (being a bit of a sandwich and toast monster).


  • Are there any benefits from drinking Beetroot juice, and if so where can I buy it from?
  • Hi Alice

    Congratulations on your weight loss, that is a brillant achievement.

    Could you give me an idea of what your eat now? T

    he fact you are doing resistance training  combined with 30-40miles of running means your exercise is spot on in my view. If you have very stretched skin it may not be as straight forward as just diet advice you need but if I was to have an idea of food intake I could certainly see if there are any dietary things you could do, if you can give me rough portions sizes that would also be good.  

    Is your running all steady or do you do some intense running such as intervals as well?

  • There's a definite SIDE EFFECT of drinking it KR - red wee! image
  • Hi Ruth - I have got into a really bad habbit of having a mid afternoon snack - normally a chocolate bar, bit of cake or bag of crisps.  What would be a healthier alternative, I'm not really a fan of nuts and I already would of had a apple and clemintine with my lunch.
  • SP13

    Do you practise eating/drinking whilst running most weeks on your long runs? If it is only racing you have problems with it is likely due to the intensity and/or nerves which may affect your stomach emptying rate and blood flow to digestion tract.

    Make sure you are not eating too much (or too soon or too little before a race), try main meal 3-4 hours before (but try different amounts to see if that works) then perhaps a light snack a couple of hours before start such as a very ripe banana, a liquid meal replacement (e.g slim fast type drink as liquid meal will empty form stomach quicker) 1/2 a sports bar but watch portions when only 2 hours or less until start. Then I wonder if you are waiting to eat & drink until too far into race, you should have something little and often, if you become dehydrated before you start drinking and eating this can cause more problems. Could you try one jelly chew (choose one with electrolytes in them) say one every 15minutes and then just sip on water about every 5 km, don't gulp the water hence why you should practise. Start race well hydrated but don't over do the drinking, say 500ml at leat meal 3-4 hours before then sip on a further 250-400ml up until start of race.

    We all have different reactions with food/fluid during intense exercise but you should practise lots on long runs and rI do think  if you get the lead up to the race right PLUS little and often then you should do better.

    Good luck

  • Hi Ruth,

    I am an insulin-dependent diabetic with a place in this year's London Marathon.  Although I have run marathons previously, this will be my first as an insulin-dependent.  I currently rely on jelly babies to fuel all of my runs (you advised here last year to keep insulin doses at the usual levels in advance of even the longest runs, and that has worked really well for my HBA1c's), but I am finding that I am having to take the JBs at ever decreasing intervals as marathon training progresses (every 8-9 minutes now whereas it was every 12-13 minutes before I increased my training) - is this likely to be a function of higher metabolic rate (due to greater training volume), me having lost a few pounds, or both?  Will this effect level out, or should I be introducing a different or an additional fuelling strategy?

    Everything else seems to be going really well but I am always conscious that for a diabetic to get the fuelling wrong would be a total medical disaster, so any helpful hints would be fantastic.

    I am already a little nervous about how this is all going to pan out, so anything you could do to help me see my way through this would be much appreciated.

  • LIVERBIRD wrote (see)
    There's a definite SIDE EFFECT of drinking it KR - red wee! image

    As long as it doesn't smell of Sugar Puffs too - that's okay!

    Joking aside, is it any good from a nutrional point of view?

  • Thanks Ruth. I have tried on training runs too, so it's not just the nerves. But I do tend to wait until close to the end of a long run before trying to eat, and as you say I am probably a little dehydrated before I even start. I will certainly try to eat a little and often as you suggest.

    Thanks for your help. image

  • pljesq

    Binge drinking is not healthy and I would say  if this is what you are going to do anyway then don't do your long runs after a very heavy night which will often be combined with poor sleep. Try and keep hangover runs to steady runs under 45 minutes tops. Also if you have had a long run before you start drinking rehydrate for a few hours and eat well first. Alcohol is absorded into your blood stream vis stomach so make sure you have a decent meal in your stomach. Alcohol may make any muscle damage from hard or long runs worst.

    One of the problems with alcohol is that it weakens the resolve when it comes to reaching for high calorie snacks and when eating combined with alcohol this is a nightmere if watching weight. The typical advice is mix a alcoholic drink with water or diet drink but when you are on a stag do I can't see that happening! If you want to drink low calorie drinks then a wine spritzer (again on a stag do..can't see it!) or have spirits with diet drink with soda water but depends how many you have. and the alcohol percentage can be high. If you drink beer slower this may be best as you will take in less alcohol overall.  A pint of larger is about 200-250kcal, cider if very strong means a pint could amount to 600kcal  or if sweet cider about 300kcal. Alcolpops are  often full of sugar so also calorie laden. I guess the short answer is that unless you are able to drink sensible amounts this is not going to be good prep for London.

  • Hi Ruth, like many endurance women I've got low iron (ferritin measured at only 8 last April). Although I was taking in recommended levels of iron through a veg/ fish diet, it wasn't being absorbed.  I've since started eating red meat & taking supplement (Ferrograd C twice a week).  I wanted to ask: (a) what ferritin levels you think are minimum for marathon training, (b) how often I should have repeat blood tests to check, (c) how long to continue with supplement (may be connected to a & b!)

    Also, how to balance recovery with not gaining weight - how do you balance sports drinks, gels and bars as well as meals without going overboard?

  • Hi there

    Thanks for questions. It would be good if I knew in a temperate climate what you did manage to drink but you are probably fine, as you should end a race slightly dehydrated. As a rule of rule most people can loss 2% of their body weight but in temperate or cold climates this for many may go up to 3% loss or more before it affects performance so I guess if you weight yourself before and after you would get an idea- not always practical I understand! If it is not affecting your performance and you are not getting this dehydrated on a regular basis then even with one kidney this should be fine (you can check this with a doctor if concerned about this). Most elite runners drink very little during a marathron and they run okay so if you are drink little and often and starting well hydrated I would say you are probably okay as some people can with stand more dehydration than others. But if you do  a 2 hour run in lead up to a marathon suggest you weigh yourself before and after without shoes, sweaty socks/clothing etc and see what % of body weight you loss.

    Hope this helps


  • It does. Thanks Ruth.
  • Hi,

    What you hints and tips do you have for a quick to make and easy to eat breakfast before a run or gym session? Something which you can workout on but won't slow down the routine of getting ready in the morning.

    Regards Phil

  • Hi Ruth,

    When I take a gel (Go SIS) during a run/race I feel as though they have slowed me down shortly after taking them - is this due to digestion or does it mean I actually dont need it? I take a gel every 6 miles and completed last VLM in 4:15. 

    Many thanks

  • Anna

    this is really difficult for me to answer as I have no idea what you are eating, what your weight goals are or what your training is. But if you are training as much as your lifestyle allows/what is sensible build up if you are new to exercise/ running and you need to loss weight and you are not doing so with exercise, then you are eating too much. If you are losing weight steadily since starting exercise and it is weight loss that you need to achieve to help your running then just keep going and don't try and loss too much too soon and only loss to what is a healthy target .  

    Here is an outline to help (and you need to adjust portion sizes to your calorie needs to fuel training as well as aid towards your body composition goals)

    Breakfast: cereal or porridge with fruit juice (150ml-200ml) or fresh fruit & if need increase calories  add toast.

    Mid-morning fruit (unless you are training lots/high volumes/intensity/struggle to keep weight on) then you would add a further snack to this such as a rice pudding/ceral bar/sports bar etc).Plus fluid  

    Lunch: sandwich with lean filling, fruit & yoghurt or low fat pasta/rice salad or baked potato with low fat filling & piece of fruit. Some people will add a further snack to this if need the calories. Plus fluid.

    Mid-afternoon - if training after work  you may have half to full bagel/bread with banana/honey/jam topping & fluid

     After training - if  training everyday to twice a day then you should recovery with food & fluid as soon as you can otherwise if only training once per day and not at high volumes or intensity  just try and eat yout meain meal within a couple of hours after training has finished or before if if can. Tghis is where you may get confused as lots of people drink special drink  after training and this can be very appropriate for some but regular food is fine.

    Supper - fruit & or yoghurt, one slice of bread. Some people if training hard have another bowl of cereal before bed but depends on training and weight goals etc

    Other tips: eat at least five different coloured fruit and veg each day & 1-2 portions of fish per week (one oily fish if you can, salmon, mackeral, sardines etc) . Fludi little and often throughout day.

    I do hope this helps.

  • Unhinged

    I wonder if it is something to do with pre race eating. Perhaps experiment with changing with what you eat  or how much you eat before. You may need to avoid all solid food before for three hours and just take a liquid meal before hand and  avoid fruit juice & milk before running (for at least four hours), drink water through race with your chews and do not guzzle water, sip little and often to avoid taking air in. You could also try avoiding caffeine before. The fact you are training using these with no problem would also suggest that intensity is the problem so practise during more intense runs as well and make sure you are not becoming too dehydrated and satart drinking early but not too much that you become over hydrated.


  • Hi guys,

    The clock has struck two so I'm afraid we can't take any more questions but we're hoping Ruth can squeeze another couple of answers into her busy schedule!

    Thank you Ruth!


  • Thanks Ruth - will experiment a little more.

     Think the sipping of the water is also where I may be going astray. 

  • Hi there

    You should  be happy you don't want curry and chocolate when you come in!! It would certainly not help your running at least in events under 26.2 miles. The reason is likely that running in many people reduces appetite for the first couple of hours and you are probably thirsty and like milk so this is the reason milk sits well with you and the biscuits are yummy with some salt in them and also are in small portions which when you have a reduced appetite is more appealing. I often tell athletes whom it is critical to recovery fast but they have no appetite to have fluid such as a low fat milkshake or even a jam sandwich with crusts off and cut into small triangles so the brian does not see a big portion and the athlete can just nibble on it.

  • FerrousFerret

    If you continue to have probelms you should rule out any medical issues such as allergies for example coeliac (allergy to a protein in oats, barley, wheat, rye etc) or IBS etc

    If there is no known cause I would say to you (if  you think it is the gluten and/or wheat) to first just cut down to see if this helps as you admit yourself you do like these foods. If cutting down does not help and you want to cut out bread etc for a while I would do six weeks and gradually re-phase in and carefully  keep a diary of symptoms etc If it is wheat and gluten you need to look for products that are wheat free and gluten free as gluten free does not mean wheat free but often some products are both. These are well labelled these days. This is an easier way to replace these products. Also may sure you eat slowly and chew food well and you are not eating too much of any one food type/group.

  • Kittenkat

    It is really only vital to refuel as soon as you can if training hard and/long most days or if you are training twice a day otherwise it is the 24 hours picture you should look at (getting in  enough, carbs, fat and protein in the right balance to fuel your training).

    It is carbs that is most important in immediate period if need to refuel quick as the window of oppportunity to uptake carbs starts to close  after training stops so if you have not eaten within 2 hours and you are training again soon it takes longer to recovery/you cant recovery  as optimally as you might before next session. Protein is important in next meal however you  will benefit from protein with your carbs as a recovery snack if your carb intake is not enough. However it will do no harm to add protein you your post running snack or of doing resistance training but carb is the number one priority for most.

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