Taking Sugar When You Exercise Is Good for You

My last post showed how eating refined carbohydrates and drinking sugared liquids at rest can cause high blood sugar levels, increasing risk for diabetes, heart attacks and premature death. However, during exercise, sugared drinks help you move faster and stronger. It is usually safe to take sugared drinks while you exercise because blood sugar levels rarely rise too high during exercise or for an hour afterward. Contracting muscles draw sugar so rapidly from the bloodstream that there is no sharp rise in blood sugar.

• Contracting muscles help to prevent the high rise in blood sugar that follows eating refined carbohydrates during rest (1).
• Unlike resting muscles, contracting muscles do not require insulin to move sugar inside their cells (2).
• Contracting muscles remove sugar maximally from the bloodstream, without needing insulin, during & up to one hour after exercise. The effect tapers off to zero at about 17 hours (1),(3),(4).

How fast you can run, swim, ski, skate, cycle or move your muscle in any sport depends on the time it takes to move oxygen from your lungs into your muscles. Anything that reduces your oxygen requirements will help you to move faster in sports. Your muscles burn carbohydrates, proteins and fats for energy. However, carbohydrates (specifically the sugar, glucose,) require the least oxygen to power your muscles. Anything that sends sugar rapidly into your bloodstream increases passage of sugar into muscles and helps them to burn a greater percentage of sugar so you can move your muscles faster with greater strength.

Sugared drinks provide sugar to your muscles much faster than sugared solid foods. When food enters your stomach, the pyloric sphincter closes and the stomach can squeeze only the soupy liquid into your intestines. Sugared liquids enter your intestines immediately while some sugared foods can stay up to five hours in your stomach.

Recent data show that glucose-fructose drinks are far more effective than plain water or drinks that contain just glucose in leaving the stomach faster and bringing fluid into the bloodstream faster to improve hydration during intense exercise. (Scandinavian Journal of Medicine & Science in Sports, February 2010). Therefore the best drinks to maintain endurance are those that contain glucose and fructose. Exercise drinks made with high fructose corn syrup (HFCS) may have an advantage over those sweetened with cane or beet sugar.

ALL sugared drinks should be consumed only during exercise or immediately after. When you are not contracting your muscles, quench your thirst with water or no-calorie beverages.