Spent the last few days planning my nutrition for the race in Llandudno. I'm sure I've explained before how I go about doing this but for newer followers I'll go through it again ...
First of all I consider the hydration aspect. I've been weighing myself before and after every training run for a number of years now and combined with my training speed and the temperature/humidity I now have a very good idea of how much I will sweat at any given speed, temperature, humidity. That liquid needs replacing but in a long ultra it's impossible to replace all of it ... the digestive system couldn't cope with that volume over a long time period whilst running. Trial and error have shown that I can cope with 40%.
With a bit of research it's easy nowadays to find out what the mean temperature and humidity is for almost any location in the world (the data for my next race can be found here). So, with that knowledge, I know how much liquid to take on board.
Secondly, that liquid, if not water, will contain calories, carbohydrates, etc. I know that I can take on board about 250 calories per hour during a race but most of that needs to be carbohydrates and the rest mainly proteins. I know that running uses a lot more than 250 calories per hour but the human body finds it difficult to digest food and run at the same time so, for me, about 250 calories per hour is the limit. I know that other runners struggle with that amount and can only manage less than 200 whereas a lucky few can get away with 300. Trial and error again.
Thirdly, the food has to be palatable because the most nutritionally perfect food in the world is useless if it tastes rubbish. We all like different stuff and it's just a case of trying things out in less important races and long training runs. Be aware though that eating near the end of a 4 or 5 hour training run is not the same as eating after 20 hours of racing. Somehow things taste different and may be less easy to chew or swallow. It's down to trial and error again.
Lastly, but possibly more important, are the electrolytes. Particularly sodium and potassium but also calcium and magnesium. These are lost through sweat and urine and need to be replaced but, again, too much all at once can cause the body distress. As with the liquids I aim for 40%.
I learned quite a bit from my last race - ULTRArace 100 - about what works for me (and when) and now I aim to use all the knowledge gained over the past five years or so to put together a sound nutrition plan for 24 hours.
I like to have a plan so that I know in advance what food and drink I'm having and when. I also know in advance that I'm getting all the correct amounts of liquid, carbohydrates, proteins, electrolytes, etc. All the crew has to do is hand me the stuff at the correct time ... although sometimes a bit of preparation is needed. I feel that this means that I don't have to think about what to eat and /or drink so I can just concentrate on running. I don't carry a copy of the plan with me - I just let the crew follow the written instructions.
My drinks will be an isotonic sports drink and For Goodness Shakes sports recovery drinks. The food will include jaffa cakes, protein bars, energy gels, Turkish Delight, grapes, dried apricots, breadsticks and baby food.
Of course sometimes things come unstuck, for example in Brive last year the temperature was about 10 C (18 F) lower than usual for the time of year. That wasn't the main reason for my bad race that day but it did require some quick thinking and this is another area where a good crew can help.
Hope there's something here that you can use in your own racing. Whenever I'm doing this planning I'm always reminded of a quote from ChristopherMcDougall's book (Born to Run) in which Sunny Blende describes an ultramarathon as “an eating and drinking contest, with a little exercise and scenery thrown in.”
PS thanks to Matt for posting details of the New Zealand runners at the upcoming Commonwealth Championships - see the comments after my last post. See you all there. Of course it'll be fun.