EXERCISE AND ENERGY:  FOOD AS FUEL

By Dr. Karen Reznik Dolins, EdD, RD, CSSD, CDN

“I’d like to have more energy.”   More often than not, this is one of the responses I get when I ask a new client what they would like to accomplish. 
Clients seek my help for a variety of reasons.  They may want to lose weight, learn how to fuel properly for an athletic event, or control a medical condition, but invariably the energy issue comes up.  When I examine their diet and exercise habits, the reason for their insufficient get-up-and-go is usually clear.  They simply don’t see the connection between what and when they’re eating, and their energy level.
Food is fuel, plain and simple.  Our body needs fuel to stay alive, to break down and use the food we eat, and to move.  Most of us don’t think too much about how much food we need to fuel our bodies.  We eat when we’re hungry and stop when we’re satisfied.  But some either don’t recognize or don’t pay attention to these signals.  Some eat beyond the point of satisfaction and find themselves feeling uncomfortably stuffed, while others ignore hunger signals, certain that it’s best to eat as few calories as possible.  Yet whether we want to perform our best athletically, reach a weight goal, improve our health, or simply have more energy, we will achieve greater success if we consider our energy needs.

Energy, Sports and Exercise
I was recently asked to speak with a group of women training to compete in a sprint triathlon (half mile swim, 25 mile bike, 3 mile run).  Their coach explained that they were novice triathletes who wanted advice on how to fuel their training.  She then mentioned that many of them also wanted to lose weight. 
Now I’m sure that it sounds perfectly reasonable to sign up for an athletic event as a means towards motivating exercise for weight loss.  But anyone using this strategy needs to be aware that eating fewer calories than your body is using puts an athlete at a competitive disadvantage.

Going for a daily run, swim, or strength training session stimulates the body to make changes that result in better endurance and stronger, more defined muscles. 

Our muscles are fueled by a combination of fat and carbohydrate (sugar).  While fat supplies are plentiful, carbohydrate supplies are not.  Some fat and carbohydrate are stored in muscles, and the amount that is stored is increased by training.  That means that a trained person will have more fat and carbohydrate stores in their muscles than an untrained person, which is part of the reason why they have improved endurance.  Along with this stored fuel, muscles can also draw on sugar and fat circulating through the blood.  In this way, food and drinks that are consumed during exercise, as well as fat released from fat tissue and sugars released from the liver, are delivered to the working muscle.   The result:  the well-fueled tennis player battling a worthy opponent through a long match or the well-fueled cyclist riding hilly terrain for hours will stay energized longer.

Under-eating calories and carbohydrates means that efforts to improve endurance, lose fat, and build lean mass (muscle), will fail.    Muscles deprived of their preferred fuel source (sugar) will use protein instead.  The metabolism slows down and fat stores, regardless of how ample, are conserved.  Odd as it may sound, eating too little fat can also be a problem for the athlete.  Active people who eat very low fat diets have been found to store less fat in their muscles.  Since fat becomes a more important fuel source as the duration of the event increases, fat-deprived muscles will loose steam sooner than well-fueled muscles.   The longer the duration and greater the intensity of the workout, the more severe these issues become.
 
Anyone looking to have more energy to support athletic training and performance must be sure to give themselves the amount and type of fuel they need.  Equally as important, they must get it when they need it.  In my work with athletes, whether executive types, active moms, varsity athletes, or collegiate football players, I find they tend to eat more when they need less.   The student-athlete, for example, will often sleep in and skip breakfast, grab the first available thing they see between classes, then spend hours on the field training before they finally get to sit for a substantial meal.  They’re going into practice under-fueled, and trying to catch up after.  Their health, daily functioning (food fuels the brain, too), and athletic performance all suffer.

Energy, Exercise and Weight Loss
Most people who want to lose weight don’t want to do so at the expense of energy.  In fact, increasing energy levels is a goal of many attempting to shed some extra pounds, and staying energized during weight loss is a great way to make sure you stick with your meal plan.  A diet that leaves you feeling lethargic isn’t likely to last long.   
Adding exercise to a weight loss program is a great idea for a variety of reasons.  We use more calories when we’re walking, jogging, riding a bike, or swimming than we do when we’re sitting in front of the computer or TV.  We also change our metabolism, or the way our body uses fuel.  When done properly, exercise can help us use more fat for fuel.
It is common lore that exercise “speeds up” metabolism.  Actually, the research in this area is far from clear.  One reason why it’s so difficult for scientists to figure this out is variability in fuel intake.  Active people who don’t add enough food to fuel their activity can actually see their metabolism slump.  This scenario is common among people who find that they are unable to lose weight despite copious amounts of exercise.  If this is you, chances are you aren’t providing adequate fuel for basic metabolism plus exercise, and actually need to eat more.  The key to effective weight loss is to eat enough calories so that you are meeting those needs (metabolic rate plus activity) but less than your total needs (normal activity).
 
Tips to Keep Energy Levels High

  1. If athletic performance is your goal, make sure you are eating and drinking throughout the day.  Break up your meals so you are eating before and after a workout.  An active person needs at least 3 times as much carbohydrate (potato, bread, rice, pasta, vegetable, fruit) as protein (chicken, fish, meat), even when building lean mass.  For example:

    1. 1 chicken breast (covering no more than 1/3 of the plate) with a medium baked potato, sautéed spinach, salad with vinaigrette and an apple

    2. 4 oz. hamburger on a whole wheat bun with salad, broccoli, and 1 cup melon

  2. If you are training for an athletic event but also want to lose weight, make sure to plan ahead so you can lose slowly.  Do not aim for losing more than 1 pound a week in the month before your event, and do not try to lose weight the week of your event.

  3. If you are exercising to help with weight loss rather than for performance, it is safe to lose 1-2 pounds of fat a week.  Create a plate as described above, but with smaller portions and less added fats. 

  4. Always include a small amount of carbohydrate along with fluid before exercising.  Examples include a piece of toast, a piece of fruit, or a yogurt. 

  5. Stay hydrated.  Any weight lost over the course of a workout is water weight, and should be replaced.  Drink 2 cups of fluid to replace 1 pound. 

  6. Distribute your calories evenly throughout the day.  Dinner should not be your largest meal.

On-line programs such as http://www.nutriinfo.com/etools/etools.jsp can help you calculate your needs.

Dr. Karen Reznik Dolins has a private practice in Mamaroneck where she helps people of all ages and activity levels reach their health, performance, and weight goals.  She is also an adjunct associate professor at Teacher’s College, Columbia University, where she teaches sports nutrition.  For more information, visit her web-site at www.nutriciseDr.com or call 914 391 2982.