Mayoclinic.org says that type 2 diabetes – also referred to as adult onset diabetes – is a chronic condition that affects the way your body metabolizes glucose (blood sugar) – resulting in your body either resisting the effects of the hormone insulin that regulates the movement of sugar into your cells, or doesn’t produce enough insulin to maintain normal glucose levels.
Mayo comments that, “type 2 diabetes develops, when the body becomes resistant to insulin or when the pancreas is unable to produce enough insulin. Exactly why this happens is unknown, although genetics and environmental factors, such as being overweight and inactive, seem to be contributing factors.”
Research has demonstrated that exercise improves glycemic control in people with type 2 diabetes, alone, or the result of weight loss, improved insulin sensitivity, and modifications in cardiovascular risk factors like elevated blood pressure and triglycerides – a blood fat associated with an excess of simple carbohydrates in the diet.
The American Diabetes Association recommends that people with type 2 diabetes attain a minimum of 150 minutes per week of aerobic exercise and at least two weekly resistance exercise sessions, while minimizing sedentary time.
A study – Significant Dose-Response Between Exercise Adherence and Hemoglobin A1c Change – which appears in the September 2020 issue of Medicine & Science in Sports & Exercise, examining the physical activity level in individuals with type 2 diabetes over the age of 65 years in the United States, “found that only 25% met the American Diabetes Association 2007 guideline recommendations for total physical activity.”
A separate study of physical activity levels in the United States reported that, “41.1% of individuals with type 2 diabetes met the aerobic exercise recommendations compared with only 12.4% for resistance training.”
Canadian authors of this Medicine & Science study chose to examine, “whether a dose–response relationship existed between the level of adherence to prescribed exercise over a 6-month exercise intervention and glycemic control (specifically, change in hemoglobin A1c [HbA1c]) in patients with type 2 diabetes.” And, “if this association was affected by any of the following factors: modality of exercise, age, sex, or glycemic control before participating in exercise training.”
A HbA1c test, according to Medlineplus.gov, “measures the amount of glucose attached to hemoglobin. Hemoglobin is the part of your red blood cells that carries oxygen from your lungs to the rest of your body. An HbA1c test shows what the average amount of glucose attached to hemoglobin has been over the past three months.”
The Canadian researchers used data from the Diabetes Aerobic and Resistance Exercise (DARE) trial, “a single-center, randomized controlled trial designed to evaluate in type 2 diabetes the effect of aerobic, resistance, and combined aerobic and resistance exercise training compared with no exercise training on glycemic control over 26 wk.”
The aerobic exercise participants utilized a gradual intensity-based progression – with a duration to 45 min at 75% of maximum heart rate per session, while the resistance participants worked up to three sets of eight repetitions of seven exercises at an intensity of eight maximal repetitions. The combined exercise training group completed both the aerobic and resistance training components.
The control group were encouraged to maintain their usual pretrial level of physical activity from baseline to the end of the intervention period.
Dietary guidelines were recommended from the Canadian Diabetes Association – meeting 90% of the energy intake to maintain their weights during the study. HbA1c changes from baseline and the end of the 6-month supervised exercise intervention were evaluated.
It was concluded that, “a dose–response relationship between exercise adherence and change in HbA1c for aerobic and combined exercise but not for resistance exercise training. These results suggest that an increased volume of aerobic or combined aerobic and resistance exercise is associated with greater improvement in glycemic control.”
If you have type 2 diabetes or are pre-diabetic, check with your physician first for guidelines, before you begin a new exercise program.