Q. I ran the Flora London Marathon last year and took gels every 45 minutes along with water and sports drinks when they were available. Is 45 minutes about right, or too frequent or infrequent?
My feeling from last year was almost that I'd taken on too much... Neil Bolton
A.Marathon runners need 30-60 g of carbohydrate per hour. A carbo gel has around 32g of carbohydrate so, in combination with the Lucozade Sport on course, a gel every 45 minutes would give you an average of 40g carbohydrate per hour, which is well within these guidelines.
Q. At what point in a race should I take my last gel? Is there a point when there’s not enough time left for the body to benefit from it? Pies and Salad
A. It’s never too late, because it can still enhance recovery. You also have sensors in the mouth that can give you an instant lift by taking in carbohydrate. In terms of functional benefit for the race itself though, I would suggest taking your last gel around 30 minutes before you plan to finish.
Q. You mention taking on other carbohydrate sources - for enjoyment rather than fuel. I sometimes eat fun-size Mars bars as well as carbo gels - would the protein and fat content of these be detrimental to my performance, or is it just about individual choice? Fiona C
A. Chocolate bars are a good source of carbohydrate, although they’re not solely carbohydrate in the same way as carb gels are. The simple answer is: if it you like it, eat it and enjoy it. The enjoyment could even help your performance in endurance events.
Many people find gels easiest though, and they are a more concentrated source of carbohydrate. Don't worry too much about your fat and protein content – you’ll only be using them for energy during the race.
Q. I’m running in the Sussex Beacon Half-Marathon this weekend. When's the best time to take gels in a half-marathon? Bootsie
A. If you're going to be running for between 90 and 120 minutes, one gel should get you through - probably after around 50 minutes. If you’re running for more than two hours, take two gels - the first after about 45 minutes and then another after about 90 minutes.
Sweets are a good source of carbohydrate too - work out the carbohydrate content of one packet so you can calculate how much you need to meet the 30-60g/carbohydrate per hour guidelines.
Q. My marathon training includes two eight-mile runs to work each week. I do these without having any food or water first. Is there an advantage in running these shorter runs in a fasted state, to prepare for that feeling towards the end of the marathon? Bombat
A. If you don't consume anything before running in the morning, then the emphasis falls on your meal the night before. If you've eaten enough then, you could run without eating in the morning, as long as it isn’t a very long or really intense run.
However, if you choose to do this, what you eat for breakfast afterwards is even more important, both for aiding recovery and allowing you to get on with the rest of your day. Porridge, cereals and toast are all excellent options. Have some fruit juice for additional fluid and carbohydrate too.
Q. Do you think it’s better to do all your long training runs using your marathon fuel strategy (on the basis that you are preparing your body for the actual event) or to do a few runs like this to get the strategy right and then do the rest on short rations in an effort to boost your body’s fat burning? Richard_R
A. You don't need to practice your marathon fuel strategy on every long run, but the science behind promoting fat burning isn't as simple as you suggest. There is a school of thought that suggests that
if you train on low carbohydrate you are increasing the stress placed on your body and this may in turn enhance your race-day performance. However, as yet this is not well accepted, and from a practical point of view, without energy you won't be able to train for the duration or at the intensity you need to in order to achieve the finish time you want. A low carbohydrate diet also increases your susceptibility to infection.
You should be more concerned with using and supplying your body with carbohydrate than trying to use fat as a fuel source.
Q. After my harder sessions I use specific recovery products or chocolate milk, and it seems to make for far less muscle soreness and consequently better sessions the following day. Is the composition of these products different? Sue C
A. Recovery is very important for three reasons: to replace the carbohydrates you've used, to take on protein to help your muscles recover and to replace fluid you've lost trhough sweat.
The guidelines are: 1g of carbohydate per kg of body weight as soon as possible after exercise, plus 10-20 g of protein. As for fluid, drink according to the amount of weight you've lost. Monitor your urine colour in the hours after training too. The darker the colour, the more dehydrated you are. Ideally, your urine should be a light, straw colour.
Q. Rather than worry about sweat rates - which will be different depending on the intensity of my running, the temperature, wind speed etc. - why can’t I just drink when I feel thirsty? Go-KL
A. This is an interesting and ongoing debate. The most current school of thought recommends you should drink according to thirst, and to minimise a decrease in your body weight of more than 2%. But doing one of these doesn't necessarily mean the other happens. For example, drinking according to thirst might not maintain your hydration levels to the recommended standard. This is why we suggest drinking according to sweat rate.
Another key concern is that people will drink too much. Hyponatraemia is very serious and runners need to ensure they don't consume more fluids than they lose in sweat.
Q. What should I eat during the taper weeks, especially the final couple of days before my marathon? I’m a slow run-walker - will the extra time on my feet have an effect on my eating plan? Happy Camper
A. Whether you are an elite, club or amateur runner, what you do during the taper period should be very similar. Key guidelines are to consume 5-7g of carbohydrate per kilogram of body weight per day. This amount is enough to help maximise carbohydrate stores but still support your tapering training. Eating breakfast is also important, as is taking on carbohydrates around training sessions.
Don't miss our next live forum debate - part of a series in our 2009 Flora London Marathon build-up. On Thursday March 19, we'll be welcoming club coach - and Lucozade Sport Super Six mentor - Steve Smythe into the forums between 1pm and 2pm to answer your fuel and hydration questions. Pop the date in your diary now!