Micronutrients for the Endurance Athlete

Thursday, March 4, 2010 | By TrainingPeaks
 
 
 
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This article was written by James L. Weinstein, PhD, RD.

The importance of good nutrition is more well-recognized than ever before for the endurance athlete, but often, athletes find themselves at a loss when asked to describe their “nutrition plan.” Complicating the nutrition universe is an intertwined cacophony of messages coming from scientists, nutrition companies, experts, “so-called” experts, government agencies, the Internet, and others —and all this great intended nutrition information is often conflicting, confusing, and sometimes, completely wrong.

When discussing endurance nutrition with an athlete or coach, I often like to begin with the basic nutrition plan as a foundation for understanding what you are eating, what it is doing in your body, and why you might want more or less of some specific nutrient. Building on the basic science and challenging the commonly understood principles is important, but that comes after you as an athlete understand the basics of nutrition and the food you eat.

The following information is meant to help you use the tools at your disposal to better understand what you are eating and how it relates to what you need as an endurance athlete. I like to describe this as the “What, Why and How” of eating. Essentially you, as an athlete, should know what you are eating, why you are eating it, and how it is going to affect your body and performance.

How much of a nutrient do you need?

This seems like a simple question—but it has scientists and experts perplexed, consumers thoroughly confused, and important consequences for the endurance athlete. The Recommended Dietary Allowance (RDA) is the daily intake of a nutrient needed to meet about 97-98% of all healthy individuals in the age and gender grouping. Coaches and Nutrition experts often use an assessment tool at http://fnic.nal.usda.gov/interactiveDRI/ to generate a report of “basic” macronutrient and micronutrient requirements. It is much easier than trying to read the original tables of RDAs. One of the neat things with this report is that it lists the RDA and the tolerable upper limit (UL) of each nutrient you select. The latter is an important value for some who are consuming supplements from multiple sources.

Which nutrients are we talking about here?

This information begs the question, “Do athletes need more?” It is certain that Endurance athletes require higher levels of certain nutrients, vitamins, and minerals compared to non-athletes, but how much more is a very difficult questions to answer. Some specific vitamins and minerals to be concerned about include: B vitamins (thiamine[b1], riboflavin[b2], niacin[b3], pantothenic acid[b5], pyridoxine[b6], biotin[b7], folic acid[b9], and cyanocobalamin[b12]), Vitamin’s C, D, E, and minerals: Iron, Calcium, Sodium, and Potassium. I could probably make an argument that every vitamin and mineral is important for the endurance athlete and I would encourage you to speak with a dietitian about the importance of any specific vitamin or mineral in question—the purpose of this article is to simply be a primer for you to use in evaluating your dietary intake.

How do I evaluate my diet?

As a dietitian working with people on the spectrum from obese/sedentary to elite/professional athletes, it has become very clear to me what works and what doesn’t when trying to evaluate a diet. Let me share some of that experience here.

There are three key steps to evaluating your diet: 1) Keep accurate records; 2) Determine your requirements; 3) compare your evaluated intake to requirement and make some decisions. The process is relatively straightforward but as you will come to see, there is a lot of uncertainty, and the more exact you can be, the better the results. It is very important to ensure you are performing each of the three steps with an understanding of the importance of being accurate and disciplined with your data—the old axiom “garbage in = garbage out” applies. If you do not keep accurate dietary records, use accurate data to evaluate those records, or exacting, scientifically sound decisions to change behaviors, you are wasting your time.

Many athletes and coaches choose to enlist the help of a Registered Dietitian (RD) in conducting this evaluation process, and they are certainly qualified as the experts in food and nutrition. I highly encourage you to consider seeking out expert advice for an in-depth analysis of your diet and how best to develop a complete nutrition plan to meet the full complement of macro and micro nutrient requirements that you as an individual have.

Keeping Accurate Records

This is probably the most difficult part of dietary analysis. It is time intensive, absolutely necessary to be accurate, and it’s very easy to make mistakes. The food record has several important parts: time, food item description, and amount consumed. There is an entire body of literature published on both the best methodology and accuracy of using the food diary and let me summarize it for you: accuracy, accuracy, accuracy! To record an accurate food diary, you need to keep track of what you eat in intervals. For example, you will want to record foods either immediately after eating them or within a few hours. Waiting until the end of the day to record all the food you ate in a day doesn’t work; waiting until the next day is likely to lead to major errors in your data.

Food description/meal time

The first step to an accurate food diary is to simply record the food items you ate. It seems simple, but it is easy to make a mistake. For example, when recording what you ate for breakfast, it’s easy to remember the cheerios, milk, and coffee. It much harder to remember the sugar and cream in the coffee. It is important to keep time (or meal name ie. breakfast, snack, or ride food) because it provides a reference as your mind marches through the day. It helps you remember the foods you ate. It is also important for a dietitian evaluating your eating habits as it shows your meal frequency and food groupings, and may affect such things as nutrient bioavailability.

Food Quantity

Figuring out how much you ate is just as tricky as remembering what you ate! There are three basic methods here: weight, volume, or item description. For example, you either ate 75 grams, 2.5 ounces or 1 slice of Bread. Obviously, the latter is the simplest description. But how would you describe a piece of pie or a slice of pizza? We all know that you can have different sized “slices.” Poor accuracy here can cause major errors in your analysis. Doing this part right takes time and energy. The best way is to weigh or measure your food—but that’s not always possible. Do the best you can to minimize “estimating” your amount of food.

Managing your food diary with TrainingPeaks

TrainingPeaks offers a fantastic way for you to manage a food diary. By simply dragging food items onto your calendar day, you can create a food diary of food eaten or even schedule a meal plan of foods you will eat.Although the process of finding the food items is straightforward, you should take a few days of “practice” to make sure you are correctly and efficiently keeping your food diary. In addition, as you add foods to your calendar you should consider also adding the foods to “favorites.” We are creatures of habit and you are likely to consume that food again.

Another important feature to consider when searching for foods in TrainingPeaks is to know which food library you want. You will notice several choices including USDA, Packaged, Community, USDA & Packaged, and all. The USDA library should be your first choice for searching for a food as it is based on one of the primary databases that nutrition experts use when conducting nutrition analysis both for clients and research.It is a very complete and accurate library. From my experience using these libraries, I prefer to first look for food items in the USDA database. If I cannot find the food I am looking for, then I search using the USDA & Packaged database. I will ultimately go to the community database if necessary but will check the nutrition info for the food against several references I use as a Dietitian (i.e http://tinyurl.com/yc8zslt). You can do this by simply double clicking on the food item and selecting “view details.” If you see a lot of blanks in the micronutrient data then be cautious when using this item as it may have incomplete data, ultimately rendering your analysis incomplete.

How to start your food diary

  1. Start by keeping a food diary for one month. The purpose here is to basically learn the feature in TrainingPeaks, or to get good at keeping a paper diary (depending on the route you choose).
  2. After the first month, consider keeping a diary less often. A couple examples are to keep it for one week of every month or to keep it for three random days of every week (but include at least one weekend day).
  3. Keep the diary concurrently throughout the day. If you can’t log in to TrainingPeaks then simply keep a little notebook and jot down the foods and amounts you ate. This will ensure you don’t miss any food items (like that Dunkin Donut munchkin you grabbed from the box on the secretary’s desk!)
  4. Seek help from a qualified expert (i.e a Dietitian with experience in Sports Nutrition) if you have questions. This goes for coaches too! Dietitians with experience in Sports Nutrition spend a lot of time and energy helping athletes AND coaches conduct proper dietary analysis and develop suitable, personalized nutrition plans.

Helpful Tips for keeping a TrainingPeaks Food Diary

  1. When searching for foods, begin with the USDA Library or USDA and Packaged Library.
  2. When you find the food item, double click on it, and then click the “view details” link.
  3. Look at the micronutrients fields. If they are blank but you are confident the food has micronutrients, select a different choice from the library list.
  4. Once you have taken the time to ensure the food you are adding has complete data, add it to your favorites
  5. Spend some time making “Meals” of your most common foods. For example “Morning Coffee” might include the coffee, the cream, and the sugar just the way you like it.
  6. If you take vitamins, do NOT forget to add them to your favorites, or if you take several make a meal and call it “My Vitamins.” If you are tracking your micronutrients, it is important to consider the multivitamin!
  7. Don’t forget to include your workout food. I usually eat the same thing on a ride of 1, 2, 3, or 4 hours in length so I’ve created meals called “1 hour ride”, “2-hour ride,” etc… and have my typical nutrition intake listed. You can always adjust this.
  8. If you are going to add a new food, do so with a complete record of the nutrient contents of the food. My favorite reference to have in the house for just such an occasion is at: http://tinyurl.com/yc8zslt

Then compare your evaluated intake to requirement and make some decisions.

Typically, the analysis of your food diary is a laborious, painstaking process, but the advent of computerized analysis like that in TrainingPeaks has simplified the process by providing you a summary of the macro and micro nutrients you consumed over a given time period. When analyzing your diet, the key is that you want the average intake to be over several days (or more). It’s never good to assume one day is “typical” or “not typical.” It’s better to have a collection of both types of days in your analysis. Also, realize we change how we eat throughout the year. For example, we eat differently when we are logging 20 hour training weeks than when we are logging 8 hour transition riding weeks. It’s important to understand external influences on your dietary intake. As a rule of thumb, make sure you have at least three days in any analysis you are going to look at and be sure to discuss your questions with a knowledgeable nutrition expert.

Analyzing Your Nutrition

Determining if your diet is “adequate” or if you are getting enough of any one specific nutrient is something much more difficult and you should really coordinate your efforts with a Dietitian if you are going down this path. One of the most common questions I find myself answering is “do athletes need more of a nutrient that your average American.” The answer is yes but defining how much more is quite tricky. What we DO know is that there are some Upper Limits of safety for vitamins and minerals and you need to know and follow these.

A good place to start when looking to see how much of a specific vitamin or mineral you need is the Recommended Daily Allowance tables and the Safe Upper Limit (UL) Tables available at:http://tinyurl.com/y9yddxs. The RDA and the ULs are part of the Daily Reference Intakes (DRIs). Not to cause you any unnecessary confusion, but these are not the same values as the Recommended Daily Intakes, also knows as the Daily Value and used as a reference on food labels as the % DV. The Daily Value presented on a food label and also conveniently shown in TrainingPeaks is a good reference value for ensuring adequate intake of macro and micro nutrients for someone consuming 2000 Calories, but it’s important to realize that if you eat 4000 calories you don’t just double your Daily Value requirements.

Which micronutrients should you care about?

As a dietitian I care about ALL the micro and macro nutrients—but I do educate athletes to at least be aware of the “key” vitamins and minerals. With the recently added feature of Micronutrient tracking in TrainingPeaks now is a great time to become a little more knowledgeable in your intake of your B, C, D, and E Vitamin’s as well as your mineral intake of Iron, Calcium, Sodium, and Potassium. How much you as an individual athlete need and how effective your diet is at meeting those needs is a task best left to your coach and dietitian.

 

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