Running on Empty

Running on Empty

By Laurie Schubert, PhD RD LDN, Team Dietitian

As a sports dietitian, I frequently encounter people who want to talk to me – just not right now.  They want to meet right before race day!  Athletes are clearly concerned about race day nutrition.  But meeting goals on race day is about more than just having a customized nutrition and hydration plan.  Meeting race goals is based on having first-rate workouts in the months and years before race day.  In turn, those workouts are supported by superior daily nutrition habits that promote high energy levels and mental acuity.

How do you get that boundless energy and razor-sharp mind?  Fuel yourself properly.  Food is fuel for the body like gasoline is fuel for an automobile.  The human body functions like a fine automobile, except that we have three gas tanks: fat, muscle, and liver.

  • The fat tank is the largest energy source in our body.  Even a small, slender male has at least 70,000 calories in his fat tank.
  • The muscle tank stores carbohydrate that can only be used by the muscles. The tank in the muscles is moderately sized, and holds about 2000 calories.
  • The liver tank also stores carbohydrate, which it supplies to all tissues by keeping our blood sugar levels within a fairly narrow range.  In particular, the liver provides energy for the brain and nervous system.  The tank in the liver is the smallest, and usually holds about 400 calories.

Each of these tanks empty and fill at different rates.

  • Our fat stores fluctuate over months or years, based on age, gender, physical activity, and how strong our sweet tooth is.
  • Our liver tank is filled and depleted throughout the day, based on what we eat and when.  The tank is lowest right before breakfast, as the liver supplies carbohydrate to the body through out the night while we’re sleeping.  Breakfast refills the tank.  When breakfast is long gone and hunger pangs appear in late morning, the liver tank doles out carbohydrates to the blood and tissues.  It’s refilled at lunch, is partially depleted by late afternoon, and is topped off again at the evening meal.  Should any exercise occur during the day, the liver tank provides some carbohydrates to the muscles as well.
  • The muscle tank is depleted by exercise, and refills when we eat a quality snack or meal after a workout.  Depending on the intensity and duration of that workout, refilling the muscle tank can take anywhere from a couple of hours to a day or more.

Clearly we don’t want to run out of gas in the middle of a workout.  We need to refill our gas tanks so we’re not running on empty.  Quality food is necessary at the right times to keep us functioning at the top of our game.  There are a couple of key meals or snacks that will provide you with the energy you need for a workout, when you need it.

  • Breakfast.  By the time we bound out of bed in the morning, our liver has been supporting us since dinner the night before.  We might get a maximum of 15 or 16 hours out of our liver tank before we run out of gas.  Refuel with an excellent breakfast so that your liver can support your brain and other organs effectively throughout the day.
  • Before a workout.  Top off the liver tank with a high carbohydrate meal or snack that is well tolerated.  Play with food combinations and timing until you can go into your workout not thinking about food.  Don’t be full (that means you ate too recently) and don’t be hungry (that means it’s been too long since you ate).
  • After a workout, particularly if it is long or intense.  Refill your muscle and liver tanks with another high carbohydrate meal or snack soon after finishing the workout.  Again, consider tolerance and portability, since you might be consuming this at the gym or in the car on the way home from the track.

Imagine a day full of work, family, and exercise, but without proper nutrition at regular and frequent intervals.  We’d run out of gas by midmorning without breakfast.  If we don’t bother to eat until lunchtime or later, our bodies will send us signals equivalent to the flashing red gas pump in our cars.  We’d have headaches, be tired, listless, and crabby, and top it all off with an inability to concentrate and learn effectively.  Does that sound like a good foundation for any workout, let alone a workout that is supposed to take you to the next level?

Be smart with your nutrition!  Fuel your gas tanks with high-octane food to support your activities and get you to race day fully prepared to meet your goals!  What counts as high-octane food?  See my previous Coach’s Corner, Getting Back to Basics: Healthy Eating!

If you would like help developing and meeting your nutritional needs, please contact me.

Laurie Schubert is the Team Dietitian at Experience Triathlon Coaching Services.  She specializes in working with clients to meet nutritional needs and goals within the boundaries of food preferences, cooking ability, medical limitations, and budget.  She has a particular interest in sports nutrition, but gets personal satisfaction from encouraging people in weight loss, finding the right meal plan for a diabetic, and watching young children learn to enjoy a variety of foods.

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