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Avoid the Sugar Crash

By Jackie Robertson | Feb. 20, 2019, 12:35 p.m. (ET)

Sugar Intoxication

Sugar is a popular “nutrient” in western society and culture. From musical references (think: “Pour Some Sugar on Me”) to documentaries to highly-marketed sugar-sweetened beverages, sugar is everywhere. It practically haunts us—even in the sports environment. Historically, in the endurance sports world, athletes have been widely advised to consume diets high in carbohydrates. Once, I witnessed a coach recommend a stack of pancakes drenched in syrup as a pre-race meal to an ultra-endurance runner for the morning of a big race. What?! A pattern of consuming meals high in refined carbohydrates and added sugars, especially pre-race meals, is likely to cause both short- and long-term harm to an athlete.

Let’s take the pancake breakfast as an example. Temporarily, the athlete’s blood sugar will shoot through the roof, causing the all-too-familiar “sugar high.” This spike in blood sugar can cause a brief rush of energy, but ultimately is followed by the dreaded “sugar crash.” This subsequent drop in blood sugar is caused by a release of insulin from the pancreas in an attempt to regulate blood sugar. Some short-term side effects of this crash include fatigue, fogginess, inability to concentrate, and mood swings.

Chronic high blood sugar and high insulin production can lead to fat storage, weight gain/obesity, insulin resistance, inflammation and high triglycerides, which in turn, can lead to chronic diseases such as metabolic syndrome, Type 2 diabetes and coronary heart disease. Metabolic syndrome is characterized by having three of the following risk factors:

 Risk Factors Chart

Additionally, excessive sugar intake has many negative implications on athletic performance, including GI distress, frequent feedings, unfavorable body composition and impaired recovery.

Currently, the American Heart Association guidelines for added sugar consumption for adults are:

  • Men: no more than 9 teaspoons of added sugar (144 calories) consumed per day
  • Women: no more than 6 teaspoons of added sugar (96 calories) consumed per day

To put this information into perspective, the average American adult consumes about 22 teaspoons of added sugar per day. The term “added sugars” refers to any calorie-containing sweetener that has been added to a food/beverage for processing, preparation or flavoring. Common sources of food/beverages containing added sugars include sodas, energy drinks, candy, flavored yogurt, and processed sweets (cookies, cakes, pastries, etc.). Unfortunately, sugars are added into a plethora of foods some athletes may or may not be aware of, including salad dressings, pasta sauces, instant oatmeal, frozen foods, granola/protein/energy bars, sport drinks, and condiments (barbeque sauce, ketchup, and fruit juices).

I often get the question, “What about whole fruit?” Fruit is a source of the naturally-occurring sugar fructose. However, once fruit starts going through any type of processing for canning, freezing, or juicing, the potential for added sugar content increases tremendously. This is why it is so important to look at the ingredient list provided on the nutrition facts label. Look for the “added sugars” line.

The best way to avoid added sugars is to eliminate processed and refined carbohydrates in your daily nutrition plan as much as possible. Instead, try to seek out carbohydrate sources with higher fiber content, such as fruits, vegetables and whole grains. Choosing carbohydrates rich in fiber versus carbohydrates high in added sugar will help optimize blood sugar. To further optimize blood sugar for overall health and athletic performance, pair a food source of protein and fat with fiber at every meal and snack. Controlling blood sugar through food in your daily nutrition patterns is the foundation of the Metabolic Efficiency concept. By doing so, you will-train your body to become more efficient at utilizing internal fat stores for energy. As you can imagine, becoming metabolically efficient will not only improve your overall health, but your athletic performance as well.

Rather than a stack of pancakes, try utilizing the Metabolic Efficiency concept to build blood sugar-stabilizing pre-race meals and snacks. Depending on your taste preferences and digestive system, this could be a fruit smoothie with milk (almond/soy/cow) and a small amount of whey isolate, banana with peanut butter, overnight oats with peanut butter, or Greek yogurt with berries. Whole-food options that can be used during a race include trail mix (nuts and dried fruit), oat-based energy balls, rice cakes, or nut butter crackers. Some triathletes can eat real food during a race and some cannot. It is worth trying some whole-food options during a few training sessions leading up to competition. The last thing you want to do is to try something new on race day and have a negative digestive response. If you are unsure about where to start, contact one of the Sport Dietitians at eNRG Performance to help you dial in your race-day nutrition plan. 

The bottom line: Ditch the sugar and processed/refined carbohydrates as much and as soon as possible. Incorporate more fiber-rich foods such as fruit, vegetables and whole grains. Pair that fiber with protein and fat to keep blood sugar controlled, your energy levels high, your heart healthy, and your body feeling its best for your greatest performance. 

Jackie Robertson, RD, METS I is a Sport Dietitian with eNRG Performance. Jackie enjoys working with both endurance and team sports athletes, particularly adolescents and young adults. She is an avid snowboarder, mountain biker and fitness enthusiast living in Colorado. Find out more about Jackie at