Friday, February 25, 2011

Performance Eating 101

This is my first ever blog in response to a request.  A reader wants me to talk about nutrition for teenage athletes.  First, the disclaimer.  I am not a registered dietitian.  I have a degree in the humanities.  I have no certification in anything nutrition related.  What I am is a chronic researcher.  It’s in my genes or something – I just can’t stop learning.

What follows are some suggestions on how we can use fuel (a.k.a. food) to optimize our workouts, speed our recovery and lessen the likelihood of injury.  These recommendations are based on years devouring the current science on nutrition and fitness, as well as recommendations from my nutrition text books and a couple of websites, all of which I will reference.  Please pay attention to this part:  This is not meant to be specific instructions for any individual.  Instead, I am merely suggesting that there are ways we can really use our food and benefit from all it has to offer.  Specific advice for you, as an individual, can be sought from your health care practitioner or a Registered Dietitian.

Let’s begin with a very simplified view of how the system works.  We take in fuel (in the form of food) and the nutrients are then put to work in our body.  Protein is used for building muscle; carbohydrates are stored in the liver as glycogen which is made available to the muscles as a source of energy; calcium ( a mineral) adds strength to our bones.  Fruits and vegetables (which are also sources of carbohydrates) contribute vitamins, minerals and fiber which are crucial to maintaining the health of our organs and helping us fight infection and disease. Fats play important parts too but I have to shorten this discussion somewhere.

The other important thing you need to know is how the process of muscle building actually works.  When you are building muscles, you are actually causing tiny breaks or tears in your muscles. Because the muscle you had “on hand” was not sufficient  for the task, your body not only rebuilds the muscle damaged but adds on for good measure.  Therefore, what we think of as “building” is actually breaking apart and then building.  We help this rebuilding process by eating healthfully during the rebuilding phase.  If you want to learn more, here is an article on the topic written in plain English.

These days, we tend to talk about food as being either protein or carbohydrates (“carbs” for short).  We hear a lot about carbs “making us fat” and also about “good carbs” and “bad carbs.”  Really there is no such thing.  We can make healthier choices or less healthy ones, but carbs themselves are not “bad.”  In fact, they are an essential part of our living and growing and certainly an essential provider of energy for training.  Just as you wouldn’t expect a car to run without gas, you can’t expect your muscles to work without fuel!

For everyday exercise (less than 1-1/2 hours duration), the glycogen reserves we have from a healthy, well-balanced diet are plenty.  For athletes who are performing at a high level (cyclists, distance runners, endurance athletes), these stores may not be enough.  For an endurance task or one requiring a LOT of energy, loading carbohydrates beforehand will help increase these stores in the liver, making more available for the task at hand.

What this means, simply, is that before an endurance task, loading extra carbs can really help.  Many athletes eat a diet of about 70% carbohydrates for 3 days before the event.  They also reduce their training during this period, not only to allow their muscles to rest and heal, but also to help build the glycogen stores in the liver.

Dr. John Ivy of the University of Texas has done tons of research on how food and drink impacts performance.  Articles about his research are widely available but I have linked one here.   He has also co-written a couple of books if you are really serious about making the most of your workouts; the best known is The Performance Zone. In this book he gives specific information for various sports as well as charts for specific nutrients based on weight and activity.

30 minutes or so before working out, make sure you drink plenty of water, about 2 cups.  When you are low on fluids, or dehydrated, it stresses your body and that affects performance.  You need to keep drinking throughout, about 1 cup every 15 to 20 minutes.  Dr. Ivy recommends a sports drink that is 4 parts carbs and 1 part protein.

After you work out (again, we are talking about long periods of exercise – 1-1/2 hours or more) you need to replace those carbs and some protein, as well as replenish your fluids.  Most researchers say you need to eat and drink within about 30 minutes of completing your work out.  Replacing the fluids is essential and so are consuming some carbs.  Carbs won’t repair muscle, though, so you need some protein.  Some people drink a glass of 100% fruit juice with a peanut butter sandwich.  I am more inclined toward a piece cheese and whole fruit.  Find a combination that works for you and remember to get it in right after that workout.  Dr. Ivy’s window for this refueling is 15-45 minutes after the event.

We know that muscles actually break down during exercise.  Dr. Ivy’s research has shown that the muscles are most receptive to rebuilding in the first 24 hours after exercise.  There is a lot of science behind this claim that has to do, in particular, with insulin receptivity in the muscles.  What’s most important for us to remember is that muscles need to repair and rebuild!

So to reiterate the basics:
·    Before a big meet or event, eat extra carbs for 3 days.
·    Start the event well hydrated and drink lots as you go.
·    Eat and drink within 30 minutes of completing exercise
·    Eat a healthy diet with extra carbs and good quality protein in that important 24 hours after exercise.
·    A healthy, well-balanced diet through all of your life is your best bet for improving performance and preventing injury. 

 Additional sources (others are linked in the body of the blog):
This is an article on current thinking about carb loading – read the whole thing, there is an evolution that isn’t obvious in the first page!
Understanding Nutrition  by Whitney.  I love this text.  I use it all the time.

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