Blood sugar provides a quick source of energy whenever your body needs it, whether it is for essential life processes or exercise. Your glucose levels fluctuate in response to the degree in which fuel is needed. The fluctuations occur as a result of a feedback system within the body. When sugar levels decline due to depletion from exercise, your body releases more glucose to fuel your activity. Other things may also influence how these reactions occur including your body's own biology.
Energy Needs
Exercise places great demands on the body for added energy to fuel your workout. Active muscles need energy to function, the requirements being higher in proportion to your activity. Your body will use glucose in the bloodstream and break down stored sugar called glycogen in the muscles and liver. It will also use fat as an energy source. All of these chemical reactions affect the composition of your blood, which can be measured by blood sugar levels.
Hormone Response
Your blood sugar levels during exercise and for all activities are controlled by hormonal activity. When you eat, your pancreas increases its production of insulin to lower glucose to safe levels. During exercise, the opposite action occurs through the secretion of another pancreas hormone called glucagon. Glucagon is released when your blood sugar levels drop, targeting the liver for stored sugar breakdown. Once blood sugar levels stabilize, glucagon production is no longer stimulated.
Influencing Factors
Other factors can influence sugar levels after exercise. Eating a high-protein snack will have a similar effect on glucose levels like exercise does. The effect occurs as the result of other chemicals in the blood called amino acids. Amino acids form the foundation of proteins. Their presence triggers glucagon release the same way in which low blood sugar triggers its production. This helps explain why a snack after your workout can aid the recovery process through glucose.
Duration
Several things will affect how quickly your blood sugar levels remain elevated. The intensity of your activity, for example, directly impacts your energy needs. Your level of fitness also plays a role. With regular exercise, your body will adapt to relying more and more on fat reserves for energy, saving blood sugar for stressful situations or when the body needs to respond quickly to some kind of threat. If you are diabetic, your condition may impact your response to exercise as revealed through blood sugar. In these individuals, exercise may cause a drop in blood sugar. While the act of exercise causes an increase in blood sugar, the recovery period will vary with the individual.
References
- "Principles of Anatomy and Physiology"; G. Tortora et al; 2005
- Colorado State University; Glucagon; R. Bowen; June 15, 1999
- "Human Physiology: From Cells to Systems"; L. Sherwood; 2008
- University of Maryland Medical Center; Exercise - Exercise's Effects on Diabetes; May 4, 2009
