Asics nutrition webchat with Ruth McKean

Wondering how best to fuel during the marathon? If and when to start carb-loading? How to keep properly hydrated in the marathon? 

ASICS Pro Team Nutritionist Ruth McKean will be here on Friday 14 February (Valentine’s Day!) from 1pm – 2pm to talk about all things nutrition.

To join in, post your marathon nutrition questions below, or join us on the day for the webchat.



  • have the questions got to be re marathon or can they be regardiung any training or race......

  • Hi Seren, the web chat is aimed at marathon runners as the timing fits Paris and London, but I am sure Ruth will be happy to answer a general running nutrition questions, so post away. 

  • i run with a number of people who suffer from sensitive/irritable bowel issues.  Gels appear to cause them particular problems.  However doing the full 26.2 without anything (at race speed) is difficult.  Can you advise on anything that is easier on the bowel?




  • Hi Ruth, what are your thoughts on chia seeds? They seem to be very popular since "Born To Run" but see there are potential side-effects. It would be great to hear your view on them!

    Related stories:


    Warning on side-effects: 

    Many thanks, Gurjit


  • I am running London this year, having broken my marathon cherry in Edinburgh in 2012.

    I struggled during the race, and with a subsequent marathon later the same year, around the 20mile mark and I am pretty sure it was due to insufficient fueling ...

    I am most interested in when I should start to 'fuel up' in the days running up to the run and the best options food wise.

    For the day itself, I have been experimenting and have found a breakfast routine that suits (porridge & banana) and my race fueling is looking like clif shot blocks as I find them easy to take on the run, easy to digest and they seem to provide the right energy at the time.

    My issue just seems to be eating in the run up to the big race image 

    thank you


  • Dear Ruth,

    I have the same question as Karen (above). I know we're all different and there's no perfect fit but what can I do to best prepare, food wise, in the days before a marathon? I tried to carbo load for a marathon last year (my first one) and just felt uncomfortably full and heavy before the race.

    It's a huge topic and the answer probably varies from person to person but any snippets of advice would be gratefully received. I'm preparing for Paris right now!

    Many thanks


  • Hi Ruth, I'm running London in April and this will be my first marathon. Any advice on what to take in the final 3rd of the race to give me that extra energy I'll need to get me to that finish line. Thanks. Darren image

  • Hi Ruth,

    I am training for a marathon and have found that SIS Gels work really well for me, but all energy/sports drinks that I've tried make me feel sick and don't sit very well on my stomach! image

    Is it ok to run a marathon with just water and gels? I have read elsewhere to take a gel every 35/40mins which I have been testing out on my longer runs and I'm fine with, but wasn't sure if I could take that many if I'm aiming for around 4:30 marathon? Only the caffeine ones say on the back to only take 4 in a day, but I usually mix between normal and caffeine.

    Many thanks,


  • Hello Ruth

    I too am doing the London Marathon this year.  Last year during the Edinburgh marathon I suffered cramping in my quads, it was an unusually warm day after all the horrible usual British weather so was a bit of a shock to the system.  All was going to plan but at mile 16 the pain in my quads was quite unnerving, I had High 5 Gels (in 2 bottles on my waist belt) with me and the High 5 Zero tablets, all of which had no effect, the cramps didn't stop me running but made for a very uncomfortable last 10 miles. 

    I am currently trying Dextrose Glucose tablets which I place in my cheek and let dissolve whilst on my long runs.  I'm also trying a pre-run smoothie of bananas, honey, almond milk, almond butter and oats. I also carry High 5 Zero tablets to hydrate me.  Can you give me any advice to prevent the cramps returning at London please.


  • 15West15West ✭✭✭

    Hi Ruth - is it a good idea to take a gel or equivalent just before the start of the marathon, or does that mess with body's ability to burn fat needed for the duration of the race?

  • Hi Ruth

    Long or hard runs give me the shits. I can usually prevent this by avoiding fibre for a day or two before a race or hard workout.  This means my fruit, veg, and wholegrain intake is not as high as I'd like during marathon training.  I have 3 questions (greedy so-and-so, I am)

    1. Should I take a multi-vitamin to make up for not getting my 5 a day? If so can you recommend one? (I have history of IDA so take iron supplements and vit C)

    2. What fruit/veg etc should give me best nutritional bang for my fibre/pooping-farting-making buck?

    3. Is there such a thing as low GI, low fibre, high carb food?


  • I'm keen to understand how glycogen requirements vary by runner and by training.

    Is it the case that if you train yourself to burn fat efficiently (e.g. by doing long runs in a glycogen depleted state), then your glycogen stores won't deplete as fast?

    Whenever i read about how much energy you're required to take on in a marathon it takes a one size fits all approach (e.g. x grams of carb /y kg of body weight).  But surely the requirements should vary depending on fast/slow you burn through your glycogen? 

  • My query is similar to Marrows' - He phased it so well.

    I would be interested in any tips on reducing the need for 'comfort breaks' during training, but particularly during the race.  This has always been an occasional problem for me in the past, but usually manageable.  However, following advice on these fora, I've started having breakfast (porridge & dried fruit) before long runs and this has been causing me regular problems.

  • LS21LS21 ✭✭✭

    What 15West asked. Many people take a gel 5 mins before the start, and I've seen others drink a bottle of Luco Sport in the first mile. But other folk say this is a big no-no for the fat-burning reasons mentioned. Interested in your thoughts re that. Thanks!!

  • Oh dear - I think a lot of us have issues with hedge-bottom (or in my case dyke-bottom) stops on our long runs; I'm ok until I couple distance with speed!  I would like some advice on fuelling without causing these problems.  Again, like so many others, I fade during the last 10k of the marathon and I'd love some help with that; my training has been going so well this year.


  • Hi Ruth - I will be running Paris in April and this will be my 5th marathon.  Regardless of how I have fared in each of my previous races I seize up with cramp every time at the end in both legs and it is pure agony. My father used to run marathons and suffered in a similar way. Is there anything I should be adding to my diet that will help here? I am fine after long training runs (18-22m) and always ensure I am well hydrated and take gels during races. Thanks

  • MACbMACb ✭✭✭

    I am reading a book called "Mastering the Marathon: Time-Efficient Training Secrets for the 40-Plus Athlete", and the author seems to be taking quite a few gels and energy drinks the morning before his marathons. I kind of thought that the gels were for use during the race to help you at the end. he also has what sounds like a standard pre race breakfast. So isn't this kind of over loading on carbs? 


  • Hi Ruth, I have two related questions that I hope you might be able to answer. There's a lot of talk during marathon season about getting lean and reaching your ideal racing weight but I wondered whether there was any guidance on minimum BMI or how to know whether you've gone below an 'ideal'?

    I'm 5ft and currently weigh 6 and half stone. Last year, I started to feel unwell when I dipped below this weight in marathon training although I was diagnosed with iron-deficiency anaemia at the same time. I've since been diagnosed with a vitamin B12 deficiency and still take supplements for both deficiencies as I eat very little meat (particularly red meat as it triggers IBS symptoms).

    I'm starting to feel drained again but find it hard to tell whether it's due to weight or dietary deficiencies. I'd be interested in any tips for topping up on iron and B12 without eating red meat.

    Many thanks!

  • Hi Ruth. Could you give any tips for a first marathoner, aged 49, and diabetic please? I have been educating myself. I am an experienced runner and have so far ran up to 18 miles...

  • I find Morton neuromas in my foot limit my training. Do you have any nutrition tips to help?
  • I'm running Edinburgh in may- my first marathon! What is best to eat before or after long runs? Also all the training plans seems to head up to around 20 miles we started earlier and were going to train slightly higher to 23-24 miles is this wise to do so if u have the time? Thanks
  • Right......

    I'm doing a multiday event which will see me doing an ironman a day every day for several days.....


    what foods do you think would be the best to keep the energy levels up to keep going for around 18 hours a day for continuous days...

  • MinniMinni ✭✭✭

    Hi Ruth,

    I have seen a new range of sports nutrition focused on energy and recovery products for the over 35s.  

    Do the over 35s need something different to the *ahem* younger athlete?  And if so does this continue to change as one gets older?


  • Hi all

    Thanks for all your question! I will try my very best to answer these as best I can.


  • Hi Gurjit

    This is an interesting question and due to time constraint on here today I cannot research papers etc but as far as I am aware the actual clinical trials/research on humans is very limited and in these studies only small numbers of people where used however I am not saying it is not worth considering in your diet but only stating the fact that there is limited evidence backing up what claims are out there.

    The fact is it is a highly nutritional product and I read with interest that on the BBC link you posted they have asked David Niemen view (he is so well respected within the sport nutrition world) & even before I read this link I would have agreed with his summary wholeheartedly: “as a nutritional package they are wonderful…. but they are not a magic pill”. The claims about lower post meal blood sugar and weight loss may be  simple enough to explain. Chia seeds are super high fibre food (for 1 tablespoon of chia seeds there is around 4g of fibre; that is the same as what is in a  recommended portion of bran flake type breakfast cereal). Fibre fills you up and therefore can help you feeling more satisfied therefore your eat less and lose weight but the fibre would also slow down the digestion of a meal and hence lower blood sugar response to a meal so that could indeed be useful to a diabetic patient.

    The omega 3 content is high but it is in the form of alpha linoleic (ALA) acid and we know from other foods sources that we should query how much of the omega 3 is converted to the heart healthy omega 3 oils found in oily fish (EPS & DHA) as the conversion is usually very insufficient so the omega 3 content is good but the conversion of this within the body needs to be questioned but still useful!. My other point is that if someone where to start adding this  to everything they ate you could possible gain weight as I think it is around 60kcal per tablespoon so if nothing else changes in your training or life style  or diet this could happen (if say you had 4 tablespoons per day then over a week this could add a further 1680kcal - just something to think about). However it could also mean you get too much fibre; it is recommend that you aim for no more the 24g per day. I have also read that the chia when exposed to liquid has a binding effect and turns into a gel so this likely to happen in your stomach so again reason for slowing down digestion and filling you up but this is speculation from me. Therefore I do conclude also that it is not a magic food but certainly a really good food to have but a tablespoon a day is enough – too much of anything is unbalanced.image

    I hope that all makes sense and helps!



  • Sean Cassey, Marrows, Lou diamonds , Miss Kovich, Debby Mullier

    You all have similar questions so I hope you do not mind me doing a group post then I can add  few comments to each of your posts.

    Exhaustive endurance exercise such as the marathon can lead to stomach problems such as a feeling that your stomach has shut down and it becomes a real struggle to take on fluid or solids and often with other symptoms such as heartburn, burping, nausea and/or vomiting, cramps and diarrhoea. Not nice but having an understanding of why this happens can help understand the strategies to reduce the severity of symptoms.  During exercise there is a reduced efficiency of the stomach: 1) the rate at which your stomach empties is delayed 2) the contents of your stomach can much more easily come back up your oesophagus hence the vomiting for some3) secretion of acid which helps digest your food is decreased, 4) blood flow to your digestive system is slowed as blood is diverted to the working muscles. If it is very hot and humid the body needs to move even more blood to the skin to help cool you down, also decreasing blood supply going to the gut to help digestion. The blood supply can decrease so much to your digestive system it can cause bleeding of the bowel in some cases.


    What makes the above symptoms worse is dehydration (which can also cause cramps in the stomach and other areas of the body). If you are dehydrated you have less blood volume for your digestive system to spare and the harder it is to absorb fluids. The less fluid you have in your stomach the less well the stomach empties – a vicious cycle when you need fluid most. Another example of stomach problems can be very concentrated sugary foods when you are already very dehydrated this is because water has to move into your digestive system to help neutralise the sugar before it can be absorbed. Therefore it may be more important for those with gut problems to drink more than others who do not have gut problems but I not suggesting aggressive intake of fluid but little and often starting early.

     So what I advise : 

    • A low residue fibre  for 2 days before marathon (see marrows next post) and if really struggle then only have liquid meal replacements on the morning of a race- slimfast type drinks or you can buy other meal replacement drinks  in high street chemists such as complan or build up.
    • Try and establish a day to day morning routine away from race day of emptying bowels – perhaps hot drink and do not hurry “it” but wait until you have gone before you run.
    • Practice, practice and practice some more with race foods – sugary sweets gels as most people can train their guts and I suggest making you have something starting at 45minuts then every 30-45 minutes thereafter in the race (30-60g) .
    • Focus on starting early with sips of fluid (but I would say no more 150ml per hours should be needed but up to 200ml … unless your feel you need to drink more.
    • If still really struggle with trots in running and above does not work ask for medical help but only for races as this can be an effective way to stop the trots but do not use meds in training.


  • marrows wrote (see)

    Hi Ruth

    Long or hard runs give me the shits. I can usually prevent this by avoiding fibre for a day or two before a race or hard workout.  This means my fruit, veg, and wholegrain intake is not as high as I'd like during marathon training.  I have 3 questions (greedy so-and-so, I am)

    1. Should I take a multi-vitamin to make up for not getting my 5 a day? If so can you recommend one? (I have history of IDA so take iron supplements and vit C)

    2. What fruit/veg etc should give me best nutritional bang for my fibre/pooping-farting-making buck?

    3. Is there such a thing as low GI, low fibre, high carb food?


    Hi Marrows

    You are doing exactly what I would recommend to avoid bowel issues – lower fibre two days before a race. My advice would be not to take a multi vitamin and mineral – generally a waste a time! Instead on the days of long runs when not racing only reduce fibre  for a day  and also consider introducing low residue fibre foods – residue refers to the undigested part of the foods so if you avoid high fibre stringy veg, skins & chew food ready well. So you should actually eat some fruit and veg but choose from the following.  

     FOODS   TO CHOOSE : vegetables

    Potato   and sweet potato, (without skins) pumpkin, squash, root vegetables: carrots,   parsnip, swede, turnip, beetroot, celeriac,

    lettuce,   peeled cucumber, skinned & deseeded tomatoes, cauliflower & broccoli   florets (no stalks), peeled marrow, aubergine, courgette.

    All   vegetables must be well cooked. Remove skins and seeds where possible.   

    Vegetables not allowed on days before race:   

    Potato   skins, pulses – peas, beans (including baked beans) lentils, celery,   sweetcorn, peppers, raw vegetables, French or runner beans, mange tout,   radish, onions,

    Quorn,   green leafy vegetables for example cabbage, artichokes


    Fruit   allowed:

    Fruit   without pips, seeds and skins, ripe banana, canned fruit (not cocktail),   stewed fruit, avocado.

    Fruit to avoid but only on days before race

    Dried   fruit, fresh fruit with peel or seeds, unripe banana, strawberries,   raspberries, rhubarb,

     You could also try the liquid meals in the morning before a long run as mentioned above as liquid empties from stomach quicker and may help feel like you are running on an empty tummy.

     Point three – I guess a chocolate bar would fit into this category for example a mars is low –moderate GI, low fibre and high carb but also very high calorie!


  • Sean Casey 2 wrote (see)

    i run with a number of people who suffer from sensitive/irritable bowel issues.  Gels appear to cause them particular problems.  However doing the full 26.2 without anything (at race speed) is difficult.  Can you advise on anything that is easier on the bowel?


    If I am honest I do not think you could find anything easier on the bowel than a gel during a race as it is only some sugar at a time when your body needs it but it the sensitivity  of your bowel at that time to anything sugary . By taking a gel or sugar sweet it is easy to digest unlike foods with added fat or protein as the digestion with carbs start in the mouth. I think you need to look beyond the gel as to what is causing the problem, if it only happen on long runs or in marathon races then it is likely that the bouncing effect of running on the bowel means that eventually this will cause anything in your bowel to be pressed into the gut so there is that aspect that you want to exercise with as empty a bowel as possible. It is also likely you link this to gel because when you start to use gels it is at the stage when your body has low blood sugar & cortisol level are starting to be raised (due to stress of running) which may have the effect of causing even more problems so perhaps by practise with the gels or sweets may be the key for you but it will take time and you should make sure you take the gels and regular sips of water well before you get tired .





  • Hi Karen

    I agree it is worth spending time ensuring you have eaten well in the 1-2 days before a race.

    So if wanted to try carb loading then perhaps a day might look like this. I would suggest you initially do this for one day but if find this is not enough do it for two days. Plan it in advance!

    Breakfast: 60g cereal & milk & couple of slices of bread and honey/jam and large glass of fruit juice.

    Snack: 4 jaffa cakes & medium banana and 500ml of full sugar cordial

    Lunch: baked potato with beans, low fat yoghurt

    Snack: bagel & honey & 500ml of full sugar cordial

    Dinner – 100g dried weight pasta in tomato with tinned fruit salad and 500ml of fruit juice

    Supper – bowl of cereal or some toast and jam/honey before bed.

    The above should have around 550g of carbs so could work well if you weigh around 60-70kilos.

    I would not worry about meat and fish etc for the days you are carb loading to keep overall calories down and getting as much as you can from carbs. Reduce this down if struggle with portions etc but keep the frequency of eating up.

    Breakfast on morning of race: cereal/toast 3-4 hours before race then snack 90minutes before race (banana, half - full bagel/bread and jam). Practice race morning eating and carb loading before the big day

    I hope you can take something from this.

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