Physical activity for youth with diabetes

The following is an excellent review written by three researchers on the current science regarding exercise in young populations with diabetes. This paper addresses how exercise benefits people with diabetes, barriers and precautions. The following are only summary points from the review paper. A link to the official abstract is provided in the reference section below.

Body composition, physical activity participation in youth with diabetes

Youth with type 2 diabetes mellitus tend to be less fit, less active and more sedentary
The Search for Diabetes in Youth study reports approximately 90% of children and adolescents with physician-diagnosed type 2 diabetes are overweight or obese
2/3 of youth with type 1 diabetes were not participating in 30 minutes of daily exercise (TEENS study)
Youth with type 1 diabetes spend more time being inactive
In a Norwegian study, 43% of participating diabetic adolescents exceeded the recommended 2h limit on sedentary behaviors and 60% did not fulfill the recommended 60 minutes of moderate daily physical activity.
Teen girls with type 1 diabetes are less active vs boys and their non-diabetic counterparts

Efficacy of exercise

In one study, prescribing exercise increased the amount of moderate-to-vigorous physical activity from 11 minutes/d to 45 minutes/d after 6 weeks.
150 minutes of moderate intensity physical activity / week significantly decreases risk of type 2 diabetes and at a superior rate vs metformin.
There is no convincing evidence that cardiovascular events are prevented by exercise in type 2 diabetes for both adults and younger populations. However, cardiovascular events in young people is very rare. More research is needed to ascertain whether intensive lifestyle interventions would lower the risk of cardiovascular events as youth get older.
In a large cohort of adolescents with type 1 diabetes mellitus, regular structured exercise (30 - 40 minutes a day of aerobic, anaerobic, strengthening, neuromuscular and balance training, 3 times/week was shown to lower waist circumference, hemoglobin A1c and insulin requirements.

Exercise and Diabetes Prevention

More research is needed to convincingly report that physical activity will reduce the risk of diabetes.
Physical activity modulates the immune system and induces beneficial changes in the pattern of cytokine production and release. Thus, this may have an antioxidant effect on failing pancreatic beta cells and the overall autoimmune nature of type 1 diabetes.
More isometric strength and cardiorespiratory fitness in youth with beta cell dysfunction and insulin resistance decreases various indices by the time these youth enter young adulthood. However, more research is needed to draw firm conclusions.

Barriers to exercise

Time, work, lack of access to facilities, lack of motivation, negative body image, embarrassment, fear of failure are common barriers to exercise for adults. It is likely that similar barriers exist for young people.
An Australian study reported girls cite: lack of energy, lack of time, negative self-image, a sense of disease stigma as barriers to exercise.
Barriers are similar between those with type 1 and type 2 diabetes however, overweight associated issues of social stigma and discomfort may be of greater relevance in type 2 diabetes.
Parental modelling through action-oriented support instead of merely verbal cues is more effective in promoting physical activity.
Positive peer support may be beneficial, but not as much as family support.
Activities should be enjoyable.

Hypoglycemia and exercise in type 1 diabetes

Parents are often afraid of the hypoglycemic effects of exercise. However, the use of continuous glucose monitoring systems and insulin pump therapy allow for on-going monitoring of glucose and a degree of predictive power, thus making it easier to prevent hypoglycemia.
Aerobic activities tend to increase the risk of hypoglycemia more than resistance type activities. However, reducing basal and bolus doses of insulin is recommended for both types of activities (more so with aerobic activities) regardless of whether carbohydrate supplementation was ingested.
The main reason for hypoglycemia during aerobic exercise in type 1 diabetes is that glucose production by the liver is somewhat limited because of residual insulin in the portal circulation after exercise starts. Young people with T1DM also tend to have poor counter-regulatory hormonal measures against hypoglycemia.
Late-afternoon activity is riskier because insulin sensitivity is increased during exercise as well as 7 - 11hrs later during the night time. Morning exercise may be preferable.

Hyperglycemia and exercise in Type 1 Diabetes

Aggressive insulin reduction, forgetting to take insulin and over-consuming carbohydrates may lead to hyperglycemia
High intensity aerobic activity (greater than 80% VO2max) and anerobic activities like sprint training may increase risk for hyperglycemia soon after exercise. Sprint training increases catecholamines and lactate production which promote a rise in glycemia by reducing glucose disposal into muscle

Similar precautions to avoid hypo and hyperglycemia should be taken for Type 2 diabetes.

Conclusions

Young people with type 1 and 2 diabetes often do not meet the recommended 60 minutes of moderate-to-vigorous activity/day guidelines. However, physical activity and exercise are beneficial in diabetes when conducted with the necessary precautions against hyper or hypoglycemia. Enjoyable activities taking into consideration the perceived barriers of individuals is important. Family and peer-support will increase chances of success in adopting a healthy, physically active lifestyle. Physical activity and exercise is highly recommended for diabetic populations.

Reference

Pivovarov, JA Taplin, CE, Riddell MC. Current perspectives on physical activity and exercise for youth with diabetes. Pediatric Diabetes. 2015.:16:242-255