Metabolic efficiency refers to the body’s efficiency in utilizing its internal stores of carbohydrates and body fat at various intensities of exercise and at rest. Our bodies constantly burn a mix of carbohydrates and fat to fuel us through our daily activities and exercise.  As intensity of exercise increases, the body naturally starts to burn a higher percentage of carbohydrate and a lower percentage of fat for energy; this is simply how the human body works.  After as little as 2 hours of moderate to intense exercise, the body’s internal glycogen (carbohydrate) stores may be depleted, causing a noticeable dip in energy levels or what endurance athletes commonly refer to as “bonking”.

But, did you know that with strategic nutrition and exercise adaptations, the body can actually learn to burn more fat at higher intensities of exercise, thus preserving our limited supply of glycogen and preventing or delaying onset of “the bonk”?  Eating a metabolically efficient diet can bring about other benefits such as decreasing the risk of gastrointestinal (GI) distress during exercise, improving body weight and composition, and improving health markers.

The standard American diet is very carbohydrate-centric, and many people are accustomed to over-consumption of breakfast cereals, bagels, muffins, bread, pasta, refined grains and starches, snack crackers, cookies, candy, and soda.  But, what most people don’t realize is how much added sugar is lurking in other foods, including foods often perceived as “healthy”:  flavored yogurt, salad dressings, marinades, soups, sauces, those fancy flavored coffee drinks, granola bars, energy bars, and bottled iced tea and juice beverages, to name a few.

Over-consumption of sugar and carbohydrates is the basis of metabolic inefficiency; that is, a body that always, or almost always, burns more carbohydrates than fat as its fuel source.  Simply put, eating carbohydrates teaches the body to burn carbohydrates as its predominant form of fuel.  This in turn leads to poor utilization of the body’s fat stores; an increased need for supplemental carbohydrates during exercise; increased risk of GI distress during exercise; and higher body weight and body fat (which we know are linked to increased risk of various chronic diseases).

This series of Metabolic Efficiency blog posts will introduce you to the concept of metabolic efficiency and how you can teach your body to burn body fat as its predominant fuel source, even at relatively higher levels of exercise.  If you are interested in becoming more metabolically efficient, you can start now by decreasing the quantity of added (refined) sugars you’re consuming. Replace that flavored yogurt with plain yogurt topped with fresh berries; swap out your mid-afternoon granola bar for a handful of raw almonds; replace soda and sweetened beverages with water (add a spritz of lime or lemon juice for some flavor); opt for plain rolled or steel-cut oatmeal topped with cinnamon, butter, and chopped nuts instead of the flavored single-serving varieties.  Become a thorough label reader: scan the ingredients and try to avoid savory products (ie, soups, sauces, marinades) that contain a form of sugar in the ingredient list.  Having a hard time finding a salad dressing without added sugar?  No problem – simply mix up equal parts of olive oil and red wine vinegar, or olive oil and balsamic vinegar, or olive oil and lemon juice, and you’ve got yourself an easy, homemade option that is not only free of added sugars, but also free of icky preservatives/stabilizers.

Next up in the Metabolic Efficiency blog series: Why excessive sugar and carbohydrates in the diet often lead to weight gain and health problems.

Anne-Marie Alderson is an ITCA-certified Triathlon Coach specializing in Metabolic Efficiency.  For a list of Metabolic Efficiency workshops she is offering, check out the Steel City Endurance Events Page.