The Glaring Omission on This Site
Ever notice there is a subject that doesn’t really get discussed much here? Well there is, and I was called on it the other day. Someone asked me about what I prescribe for race day nutrition, and more specifically Ironman race day nutrition. While I have certainly offered stories of my own and other’s experiences with what I should and shouldn’t have eaten on race day, I don’t tell people what they should eat. Why? Good question.
There are as many diets as there are shades of colors. There’s Atkins, South Beach, Vegan, Paleo, Clean, Carblovers, Mediterranean, among many others. Ever go to the diet and nutrition section of the book store or library? There are tons and tons of books, each with a different approach as to how to get healthier or lose weight. Some of the books are written by idiots, but there are lots of others that have doctors and dieticians standing behind them. How can so many people who are trained and educated in the field have so many different ideas about diet? Well, a lot of times, people take a thread from the canvass of nutrition and capitalize on it. Scientists discover that when X is consumed in greater quantities, that Y happens. So they write a book all about X. Does the diet work? For the right person, you bet. They also play on people’s preferences and emotions. Like bacon? then try the bacon diet. Want to feel like you are doing your part in this world? Try the Hippie Green diet. You get the idea.
It’s not that I’m some uneducated boob on the subject. In fact, I probably know and understand the how’s and why’s better than most people who fire off nutrition advice. I have a degree in biology with an emphasis in health science, and have sat in lectures and read more articles over the last 20 years than I care to remember on the subject. So I don’t avoid the subject because I don’t know about it. I avoid the subject because I DO know about it.
First off, it’s a potentially dangerous question. I’m not a doctor nor a dietician so it would irresponsible of me to give specific direction to ones diet. And there are legal ramifications for doing so. What if I suggest some herbal supplement and it reacts with some obscure medication you were taking? What if the race day food I tell you to use contains soy based products and you are predisposed for Crohn’s Disease? What if my directive sets off your asthma? The list of genetic issues is long when it comes to diet, and to advise on something without doing your homework is ill advised in my opinion.
But genetics, drug interactions and allergies are just part of the equation. There’s also lifestyle. If someone eats lots of carbohydrates daily, take a wild guess as to what their body has adapted to utilize more of? Likewise, the person who tends to eat more protein will burn a richer mix of protein and fats when they workout. Add to that the workout itself. If do a lot of high intensity training sessions where you often hit or exceed your lactate threshold, your body has grown accustomed to switching off all fat oxidation (burning) capabilities (which is what happens right at or above LT) and using just sugar for fuel. Conversely, if you are one that trains at more fat burning friendly intensities, you body has adapted to burning more fat while you workout. So to give the fat burner gobs of calories in the workout is likely to throw him into some digestive distress, and a lower calorie diet would most likely cause the sugar burner to bonk. So how do you find out what you burn? A metabolic cart is one way. It measures the ratio of sugar/fat that you burn as various intensities. Since I don’t keep one handy on me at talks or group rides, I stay vague in my answer.
Beyond all of that, you’re still left with personal preference. All the caloric math in the world won’t help some people choke down a banana. Others gag at the smell of certain energy bars. So if some “expert” tells you to drink a bottle of perpetuem every 2 hours and you don’t like the taste, come hour 5 when that sludge is warm you’ll will be falling off the schedule. So you have to eat what you like, or at the very least, eat what you don’t hate.
Then comes hydration. If you’ve ever Googled “How much should I drink during exercise”, you won’t get off the first page of results before you see “the test”. Weigh yourself before you go run, then weigh yourself after. The weight lost is the amount of water you need to drink, right? Wrong. So when I weigh myself before and after in 55 degrees it will apply in July? Fact is the rate you lose water will vary every day, not to mention the fact that the net weight isn’t just water. Additionally, not everyone can absorb the same amount of fluid. Drinking a liter of water might only net you 50% of that back in the blood stream, and that depends on various factors like heat, intensity, etc.
Then you have the conditions. Ask a guy like Professor Tim Noakes or someone from Canada and they will tell you to drink by thirst. Let your body’s thirst be your guide they say. But if you ask the head doctors in Kona or someone who lives in Texas, they will tell you to drink well before you’re thirsty and be sure to take electrolytes with it to avoid hyponatremia. And they’re both right. Race in cool weather or shorter distances (Noakes study) and drinking to thirst will suit you. Go long and hit hot weather, drinking to thirst will ruin your day or worse. (A great discussion on this can be found here)
So why don’t I prescribe specific nutrition strategies you say? Because I’ve learned too much to make that mistake. Instead, I constantly encourage people to experiment during training and don’t just use what’s handy in the kitchen cabinet everytime. I know it gets to be annoying when I won’t give some people a specific answer, but it’s not nearly as annoying as puking or shitting yourself in a race because you read some article that claimed to “know”.
So go experiment. And afterwards, tell me what worked and what didn’t while we drink a cold beer. That I will prescribe. Happy Training.