Diabetes is a common problem affecting 34 million Americans. About one in five adolescents and one in four young adults is living with diabetes, and these numbers are expected to rise as the obesity epidemic is ongoing. Between 1990 and 2010, the number of people living with diabetes in America tripled.
Statistics in the United States
In general, diabetes is characterized by inadequate levels of insulin, a hormone produced by the pancreas. Insulin helps move sugar from the bloodstream into the various cells in the body.
People who have diabetes for a long time can experience a variety of complications, including heart attacks, strokes, kidney failure and vision loss. In fact, diabetes is America’s seventh-leading cause of death.
Two types of diabetes, Type 1 and Type 2
In Type 1 diabetes, also known as juvenile diabetes, the body does not produce insulin. The treatment for Type 1 diabetes, then, is to give the patient insulin. Many people use an insulin pump – a small, computerized device that mimics the way the human pancreas works. It administers small doses of short-acting insulin continuously, as the body normally would. It also continuously monitors the sugar levels in the blood so when a meal is eaten, the pump can give extra insulin to help transport the sugar into cells where it can be stored.
In Type 2 diabetes, the body makes insulin, but either there is not enough or the cells don’t recognize it so don’t use it. Before the obesity epidemic, Type 2 diabetes was nearly unheard of in youth, but now, there are increasing rates of Type 2 diabetes in youth and young adults. The treatment for Type 2 diabetes depends on the reason the cells can’t recognize the insulin – some people can take pills that help get the sugar in the cells; some people also add insulin to supplement what the body makes.
Exercise is recommended for all people with diabetes, and athletes with diabetes have achieved incredible success. When people play sports, their cells require more sugar to keep up with the demands placed on the body but this is balanced by the fact that exercise actually increases insulin sensitivity. Before starting an exercise program, a diabetic athlete will need to have a conversation with his or her physician about the typical demands of training and competition. Since activity affects blood sugar levels, athletes will need to come up with a strategy to participate in sports safely while monitoring blood glucose. Activity will likely mean that the student will have to adjust his or her diet and insulin dosing, so this is a necessary conversation to allow safe and effective athletic performance.
Energy Use in Exercise
Both aerobic and anaerobic exercise are great for diabetic athletes – when done carefully. Besides improving one’s mood and heart health, exercise also aids in weight loss, makes the body better at processing sugar, and makes cells more sensitive to insulin.
To understand diabetes, it is important to understand how the body makes energy and how the muscle cells convert what the body makes into ATP – the energy-carrying molecule found in all living cells. The body breaks down the carbohydrates ingested into sugar that is absorbed into the blood. For a cell to use the sugar as energy, the sugar needs to get in the cell. Insulin transports the sugar from the bloodstream into the cell. If the sugar cannot get in the cell, such as a muscle cell, that cell cannot contract and is weak. If the sugar cannot get in a brain cell, the person feels tired and can become unconscious.
The cell’s form of energy is ATP. Cells normally have a little bit of ATP stored (enough for about 10 seconds of activity) but soon rely on the body to break down sugar stores, increasing the amount of glucose in the blood, which is then brought into cells, and converted into ATP. This form of ATP production only lasts a few minutes.
If the exercise continues, the body then shifts to longer lasting forms of energy production, such as proteins and fats which are broken down into sugars, that again need to be brought into the cells to be converted into ATP. This form of energy production can last for hours and is the most efficient form of metabolism.
After exercising, the body works to replenish the stores of energy that had been depleted.
Protocol for Athletes
While athletes can and should check their blood glucose levels regularly – typically one hour before activity, 15 minutes before activity, and then at 30- to 60-minute intervals as needed – there are insulin pumps that can check the sugar level and adjust the amount of insulin given automatically. There are two broad kinds of pump systems – those with a tube and those that are tubeless.
In general, insulin pumps should be padded and securely attached to the body or removed (if possible) during contact sports and the pump site be protected with a dressing or a pad. Waterproof pumps are available for swimmers.
Rigorous activity can affect an athlete’s blood glucose level and it is complicated to regulate, so sideline personnel must be aware of the signs of abnormal blood glucose levels; if the level gets too low, it is rapidly fatal.
Since exercise is recommended for people with diabetes, there are more diabetic athletes participating in sports than ever before. However, this requires everyone on the sideline to be aware of who is diabetic so that they can watch for signs of danger. When encountering an athlete who has collapsed, prior knowledge that they are diabetic can be life-saving. Administration of a little bit of sugar under the tongue can revive a diabetic athlete whose sugar level has gotten too low. Since placing some sugar under the tongue is not harmful if the blood glucose level is high, any diabetic athlete who collapses should have some sugar placed under the tongue as sideline personnel awaits the arrival of EMS.
Dabelea D, Mayer-Davis EJ, Saydah S, Imperatore G, Linder B, Divers J, Bell R, Badaru A, Talton JW, Crume T, Liese AD, Merchant AT, Lawrence JM, Reynolds K, Dolan L, Liu LL, Hamman RF; SEARCH for Diabetes in Youth Study. Prevalence of type 1 and type 2 diabetes among children and adolescents from 2001 to 2009. JAMA. 2014 May 7;311(17):1778-86. doi: 10.1001/jama.2014.3201. PMID: 24794371; PMCID: PMC4368900.
https://www.diabetes.org/ Accessed January 3, 2021
https://diabetes.org/diabetes Accessed January 5, 2021
https://www.cdc.gov/diabetes/library/features/diabetes-stat-report.html Accessed January 3, 2021
Neha P. Raukar, M.D., MS, CAQSM, is an emergency medicine and sports medicine specialist at the Mayo Clinic in Rochester, Minnesota, and a member of the NFHS Sports Medicine Advisory Committee.