Ever since my son was born, I've had problems with
food. I don't mean bulimia or anything
like that. What happened is that
something in my digestive system changed, and the result was that if I eat
wheat or milk (plus a few other odd things like quinoa and garlic), I suffer
afterwards - weird symptoms from indigestion and bloating to depressed immune
system. It was several years of
continual illness before I worked out what was wrong.
So I am very particular about what I eat. But to add to these difficulties, I recently
read about ongoing research into Alzheimer's Disease, which suggests that it is actually a form of diabetes - now occasionally referred to as "Type
3". The current theory is that a
diet high in fat and sugar can destroy the ability of insulin to work its magic
in the brain - where, as it turns out, it is important in laying down
memories. The scientific ideas are a
little too complex to go into here, but the short version is that consuming a
lot of high-GI or fatty foods is potentially disastrous for your brain.
Unfortunately, those are just the things that runners are told they should consume during training and before a race. You get these "gels" that deliver a
lot of sugar in a rush, as well as sugar-filled sports drinks, protein bars
that contain lots of sugar and starch (not to mention wheat and/or milk which I
can't eat), and all these things are supposed to help you fill your muscles
with glycogen (rapid energy supplies) so you can run efficiently. Endurance runners are also supposed to eat a lot of carbohydrate-rich foods like bread and pasta for an extended period before their race.
I just can't help but have my doubts. First of all, I am no lean runner - I'm
overweight (BMI 23), carrying a lot of flab around my belly where it's said to
do the most harm - why can't my body use that for fuel? Also, Alzheimer's Disease runs in my family,
and I'm not keen to do something potentially harmful to my brain in the long
run, even if the running does my heart and circulation good. I don't consider brain damage an acceptable
trade-off for a healthy heart.
So I've had to go to the research in hopes of some sign that
there are other points of view. PubMed
makes abstracts of most medical research available to the public for free. Although you don't generally get the full
article, the service at least gives you the conclusions - it's a start. And so I was delighted to discover "Glyceamic index, glycaeamic load, andexercise performance" in Sports
Medicine, an Australian journal. Although the conclusions are very verbose and
disorganised, they boil down to this - the jury is still out, and more research
is needed. In particular, it's not
wholly clear what the trade-off is between a normal diet for an extended
period, and high-GI consumption immediately before and during the race. There are also questions about how all this
relates to post-run recovery.
My conclusion: I don't have to follow the advice on carb
loading, but it would be advisable to experiment and see what works for
me. No one knows best, but experiments
will at least let me test out different strategies and draw conclusions for
this sample size of one. Conveniently,
this is the conclusion of a review article collecting results of a variety of
articles on this topic. We're encouraged to "let practical issues and individual experience dictate the use of HGI or LGI meals and supplements before, during, and after exercise." Marvellous - though of course that leaves me the difficulty of figuring out what I can actually eat....
