The use of sugar as a quick source of energy, particularly just before or during exercise, to enhance performance. Contrary to popular belief, consuming high quantities of sugar 30–60 minutes before exercise does not boost short-term energy sources. In fact, it may have a negative effect by stimulating the production of insulin thus causing the sugar to be converted to glycogen. This would cause hypoglycaemia, a lowering of blood sugar, which makes a person feel lightheaded and interferes with the ability to exercise. Sugar consumed during exercise may improve stamina and is unlikely to lower blood sugar levels because insulin production is inhibited by the exercise. See also energy drink and insulin rebound.
Subjects: Medicine and Health.