Ruth is a leading sports dietician and a member of the British Dietetic Association and Health Professional Council. She is also an advisor to Sportscotland's Institute of Sport, specialising in helping athletes of all levels prepare nutritionally for competition.
This spring, she joins us as the ASICS Super Six dietician and is working closely with our marathon contenders as they prepare for the Paris Marathon on April 10. Follow her advice - and post your own questions - in the relevant forum threads.
Read the whole forum debate
Q. I have been on a rather big weight-loss journey. Having lost just over ten stone in the last year and a half, I'm happy to say I'm now at my target weight of just over nine and a half stone (I'm 5 foot 6).
I now run between 30-40 miles a week and cross-train with weights and a resistance band on my rest days.
I'd like to now reduce my body fat percentage and increase my muscle mass - preferably without changing my present weight. I'm a vegetarian and I'm unsure what I should be eating to achieve this. GemmsyB
A. Congratulations on your weight loss, that is a brilliant achievement. The fact you are doing resistance training, combined with 30-40 miles 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. However, if I was to have an idea of food intake, I could certainly see if there are any dietary things you could do.
Q. I have completed six 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 bananas - I just don't seem to be able to take any food on board. I run marathons and train on water alone and I'm pretty sure my times would be better if I could learn to take on food. How can I train my stomach to accept food? SP13
A. Do you practise eating or drinking while running most weeks on your long runs? If it's only racing you have problems with, it is likely to be due to the intensity or nerves. This 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 and eat your main meal three to four hours before - try different amounts to see if that works. Then perhaps have a light snack a couple of hours before the start such as a very ripe banana, a liquid meal replacement - for example a Slim Fast type liquid meal will empty from your stomach quicker - or half a sports bar. However, make sure you watch your portion size when there's only two hours or less until the start.
I wonder whether you are waiting to eat and 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 jelly chews? Choose ones with electrolytes in, have one every 15 minutes and then just sip on water about every 5K. Don't gulp the water, hence why you should practise. Start the race well hydrated but don't overdo the drinking. Have approximately 500ml during your last meal three to four hours before, then sip on a further 250-400ml up until start of race.
We all have different reactions with food or fluid during intense exercise, but you should practise lots on long runs. I think if you get the lead up to the race right, and refuel little and often, then you should do better. Good luck.
Q. 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 or strong option and refrain from too much alcohol, do you have any tips for low-calorie boozing? pljesq
A. Binge drinking is not healthy. 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 absorbed into your blood stream via the stomach, so make sure you have a decent meal. Alcohol may make any muscle damage from hard or long runs worse.
One of the problems with alcohol is that it weakens the resolve when it comes to reaching for high calorie snacks. When eating combines with alcohol, it can be a nightmare if you're watching your weight.
The typical advice is to mix an alcoholic drink with water or a diet drink, but when you're on a stag do I can't see that happening! If you want to drink low calorie drinks, then have a wine spritzer (again on a stag do...can't see it!) or have spirits with diet drinks or with soda water.
It depends how many you have and the alcohol percentage can be high. If you drink beer slowly this may be the best option, as you will take in less alcohol overall. A pint of larger is about 200-250kcal, cider - if very strong - could amount to 600kcal a pint, or if it's sweet cider about 300kcal. Alcopops are often full of sugar, so are 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 preparation for London.
Q. I have a question about hydration. The two marathons I have completed have both resulted in me producing extremely dark brown urine, 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.
Should I be concerned that I am getting so dehydrated if the level improves on its own with no intervention? LIVERBIRD
A. It would be good if I knew in a temperate climate how much you managed to drink, but you are probably fine, as you should end a race slightly dehydrated.
As a rule of rule most people can lose two per cent of their body weight. However, in temperate or cold climates this may go up to three per cent loss or more before it affects performance. I guess if you weigh 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 you are concerned).
Most elite runners drink very little during a marathon, so if you drink little and often and start well-hydrated, I would say you are probably okay, as some people can with stand more dehydration than others.
If you do a two-hour run in the lead up to a marathon, I suggest you weigh yourself before and after without shoes, sweaty socks and clothing, and see what percentage of body weight you lose.
Q. I need some advice on how to make sure I'm eating enough to fuel my training. I just get so confused with all the different things I read. How much is enough? Anna Williams 13
A. 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.
However, if your training is a sensible build up if you are new to running and you need to lose weight, but you're not doing so with exercise, then you are eating too much.
If you are losing weight steadily since starting exercise, and it's weight loss you need to achieve to help your running, then just keep going and don't try and lose too much too soon. Only lose weight until you reach a healthy target.
Here is an outline to help you. You'll need to adjust the portion sizes to your calorie needs to fuel training, as well as aiding your body composition goals.
Breakfast: Cereal or porridge with fruit juice (150ml-200ml) or fresh fruit. If needed increase calorific intake by adding toast.
Mid-morning: Fruit (unless you are training lots/high volumes/intensity/struggle to keep weight on). If you struggling to keep weight on or are training intensely, you could add a further snack to this, such as a rice pudding, a cereal bar or sports bar. Also have some fluid.
Lunch: Sandwich with a lean filling with fruit and low fat yoghurt. Alternatively have pasta/rice salad or a baked potato with a low fat filling and a piece of fruit. Some people will add a further snack to this if they need the calories. Plus fluid.
Mid-afternoon: If training after work, you may have half to a full bagel or sandwich with a topping of banana, honey or jam topping. Plus fluid.
After training: If training every day or twice a day, you should recover with food and fluid as soon as you can. If you're only training once a day and not at high volumes or intensity, just try and eat your main meal within a couple of hours after training has finished or before, if you can. This is where you may get confused as lots of people drink special drinks after training. This can be very appropriate for some people but regular food is also fine.
Supper: Fruit, yoghurt or one slice of bread. Some people, if they are training hard, have another bowl of cereal before they go to bed, but it depends on training and your weight goals.
Other tips: Eat at least five different coloured fruit and vegetables each day and one or two portions of fish per week, one of which should be oily fish if you can: salmon, mackerel, sardines). Take fluid little and often throughout day.
Q. I struggle to use gels during my long runs - I just don't like the taste or texture - so I've been trying out Clif Bar Shot Bloks for my last two marathons.
During long slow runs, I have been taking one Blok per mile from mile four onwards which seems to work. However, on race day this strategy doesn't seem to work well for me and I end up with an 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? Unhinged
A. I wonder if it is something to do with pre-race eating. Perhaps experiment with changing what you eat or how much you eat before the start. You may need to avoid all solid food before for three hours and just take a liquid meal.
Also, avoid fruit juice and milk before running for at least four hours, drink water throughout the 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 race.
The fact you are training using these with no issues would also suggest that the intensity is the problem, so practise during some more intense runs as well. Make sure you are not becoming too dehydrated and start drinking early, but not too much so that you become overhydrated.
Q. Why is it throughout my long runs I crave everything from a curry to a chocolate bar, but when I get home all I can stomach is a glass of milk and malted biscuits? Muppley
A. You should be happy you don't want curry and chocolate when you come in! It would certainly not help your running in events under 26.2 miles.
The most likely reason is that running reduces many peoples' appetites for the first couple of hours. You are probably thirsty and like milk, so this is the reason milk sits well with you. The biscuits are yummy with some salt in them and are also in small portions, which when you have a reduced appetite is more appealing.
I often advise athletes who have no appetite but need to recover quickly, to have low fat milkshake. They could also have a jam sandwich with the crusts off and cut into small triangles, so the brain doesn't see a big portion and the athlete can just nibble on it.
Q. 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? What sort of things can I replace it with - I'm a bit of a sandwich and toast monster? FerrousFerret
A. If you continue to have problems you should rule out any medical issues, for example you might have a celiac allergy (an allergy to the protein in oats, barley, wheat and rye) or IBS.
If there is no known cause, I would say if you think it is the gluten or wheat, to first just cut down on these to see if this helps - you admit yourself that you do like these foods.
If cutting down does not help and you want to cut out bread for a while, I would do six weeks and gradually reintroduce it, while carefully keep a diary of symptoms.
If it is wheat and gluten you are cutting out, you need to look for products that are both wheat-free and gluten-free, as gluten-free does not mean wheat-free, but often some products are both. Products are generally clearly labelled these days.
Also make sure you eat slowly and chew food well and that you are not eating too much of any one food type or group.
Q. How important is it to eat within 20 minutes after a training run or race? And what should you have, carbs or protein? kittenkat
A. It is really only vital to refuel as soon as you can, if training hard or long, or if you are training twice a day. Otherwise it is the overall 24 hour picture you should look at - getting in enough, carbs, fat and protein in the right balance to fuel your training.
Carbs are most important in the immediate period if you need to refuel quickly, as the window of opportunity to uptake carbs starts to close after training stops. If you haven't eaten within two hours and you are training again soon, it will take longer to recovery - you won't have the optimal recovery before the next session.
Protein is important in your next meal. You will benefit from protein with your carbs as a recovery snack if your carb intake is not enough. It will do no harm to add protein to your post-running snack, but carbs are the number one priority for most runners.
Q. Are there any benefits from drinking beetroot juice, and if so, where can I buy it from? knight rider
A. I have worked with a couple of very successful athletes who use beet juice. Beetroot juice is high in nitrate - it's also found in other fruit and vegetables, as well as cured meats.
The research has shown that it reduces the oxygen demand, hence helping with fatigue. It has been shown that eating lots of fruit and vegetables can have the same effect. Most vegetables are high in nitrates - including spinach, grapes, beetroot - as are all cured meats, and tea.
If you are using beet juice, you need to take about 500ml per day. You can break that up into two or three drinks. Drink it five days before a race and on the race morning, but perhaps not the full 500ml on race day. But beware, you get very red pee and some people have stomach issues with it, so use it in training and practise races before the main event you want to try it in.
Q. I've got into a really bad habit of having a mid-afternoon snack - normally a chocolate bar, piece of cake or a bag of crisps. What would be a healthier alternative? I'm not really a fan of nuts and I already have an apple and a clementine with my lunch. Suze78
A. Here would be a few better snack ideas instead of chocolate or crisps: granola or cereal oat bar; rice pudding; yoghurt with a handful of dried fruit; 1-2 slices of malt loaf; half a lean meat/low fat sandwich; rice cakes with banana and a drizzle of honey on top; breadsticks; a crumpet or if you really like your biscuits, just a have a couple of fig rolls or Jaffa Cakes. Happy snacking.
Q. 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 jelly babies 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 a higher metabolic rate (due to greater training volume), my having lost a few pounds, or both? Will this 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. Head Over Heels
A. I think what you mentioned about why you need more food is right, as you have got fitter you are covering more ground and hence need more fuel - a fast car uses more fuel! Make sure you are eating enough over a 24 hours period if you have increased training.
I think it should level out, but start early on the run as you are doing and you need to keep monitoring it, so just eat what you need to keep blood glucose at a sufficient level. I did know a runner who had to take a jelly sweet every five minutes. Also, have low GI breakfast to see if this helps.
It takes so much motivation to run a marathon without health complications, so a big high five to you!
Q. Like many endurance women, I've got low iron levels - my ferritin level measured at only 8ug/L last April. Although I was taking in the recommended levels of iron through a vegetable ad fish diet, it wasn't being absorbed.
I've since started eating red meat and taking a supplement (Ferrograd C twice a week). I wanted to ask: (a) what ferritin levels you think are the minimum for marathon training, (b) how often I should have repeat blood tests to check and (c) how long to continue with supplement?
Also, how do you balance recovery with not gaining weight? How do you balance sports drinks, gels and bars, as well as meals without going overboard? Doodge
A. You mention you have low ferritin (low iron stores) but not that you have anaemia (you may not have anaemia, just low stores which means you are at risk of developing anaemia).
If you have iron deficiency anaemia, then I do not think you are taking the right amount of supplementation and could be taking too little. Increasing iron from food alone would take a long time and you really should use supplements for about three months, each day at a dose prescribed by your doctor, then he may re-test you in three months.
If your ferrtin level is below 30ug/L then it may be affecting your performance. I would speak to your doctor about your level and follow his advise in supplementation. I can't emphasise this enough: do not take high dose iron supplementation without following your doctor's advice and suggested dosage.
Red meat and lots of fruit and vegetables rich in vitamin C will help, as this helps you absorb the iron from food. Avoiding tea and coffee one or two hours before and after meals may also help, as these drinks reduce the absorption of iron.
Gels should only be used in long runs over 60-90 minutes and during races. If you so wish you can use sports drinks before and after recovery if you like, but it's not necessary. If you are using sport foods as snacks this becomes very expensive and you can get your fuel from other foods. Very sugary sports foods do not help dental health either.