Hypoglycemia and Sports
By Stacy Winton, MS, RD, LD/N
Nutrition By Design, Inc.
sjwin2000@aol.com
Tel: 305-217-3711
Fax: 305-937-0735

You wouldn’t think of driving your car with an empty gas tank. Your body is no different. Whether pumping iron or running a triathlon the proper fuel can make the difference between hitting your target and hitting the wall.

What is the proper fuel? Carbohydrate in the form of glucose is the preferred source of energy for your muscles and brain. Blood glucose, muscle and liver glycogen, and fatty acids derived from fat tissue are the primary fuels burned during exercise. Your body stores glucose as glycogen in muscle tissue and in the liver. The type and duration of activity as well as the body’s ability to store glycogen will determine the proportion of each type of fuel used.

Strenuous exercise that is short in duration (30 minutes or less) relies on muscle glycogen as the predominant fuel. Prolonged exercise of low to moderate intensity utilizes a higher proportion of fatty acids. Endurance training enhances the body’s ability to use these fatty acids and spare glycogen.

How does this affect you? The average athlete or weekend warrior cannot rely as heavily on this glycogen-sparing mechanism. Hypoglycemia, or low blood sugar, develops when you don’t consume enough carbohydrate to maintain normal blood glucose levels. Quite simply, you’ll hit the wall and be stopped dead in your tracks like a car that’s run out of gas.

The best way to deal with hypoglycemia is to avoid it by making sure you are well-fueled. Don’t let the “low-carb” craze sabotage your training efforts. Carbohydrate should make up 50-70% of your total calories, depending on your training intensity and frequency. Glycogen repletion during exercise becomes important when participating in endurance exercise that lasts over 60 minutes. The easiest way to achieve this is by consuming sports drinks, gels, etc. that contain glucose polymers. This form of carbohydrate is usually well tolerated and easy for most people to metabolize. If you plan to be on the go all day, be prepared! Take non-perishable snacks and beverages so you will have a dependable energy source to get you through your day and maximize your performance. Remember, if you fail to prepare, prepare to fail!