The Power of Exercise: Enhancing Brain Health and Glycemic Control

Hi there!!!

I spent last weekend, up to Tuesday the 21st, hiking in Upstate New York.

Walking more makes me feel so much better, and many of my body aches, especially back pain, get better. The aches also improve with weight lifting, but when I walk many days in a row, my body feels better, and I experience lower anxiety.

While reading some scientific articles on exercise, I found a few articles that blew my mind. They'll help you whether you have diabetes or not.

These are the findings from my reading:

• Greater whole-body insulin sensitivity is seen immediately after exercise and persists for up to 96 hours (the more sensitive your cells are to insulin, the better use of insulin they make).

• "Physical exercise (training) both aerobic (continuous walking, jogging, and cycling) and resistance (exercise weights)...significantly reduced the plasma levels of HbA1c [glycosylated hemoglobin]...in addition, the meta-regression analysis demonstrated that this effect was independent from changes in body weight" (exercise specifically helps blood sugar control). "To note, that tight control of glycaemia is associated with a reduction of diabetes-related major clinical events."

• "Exercise training might be associated with lower mortality in diabetes."

• Exercise "increased peripheral insulin sensitivity and responsiveness" and enhanced suppression of glucose production by the liver.

• One specific study investigated walking and the increase of gray matter and found that walking 9 miles per week was associated with greater gray matter years later, and with a "reduced risk of developing cognitive impairment (mild cognitive impairment or dementia)."

• "Greater aerobic fitness appears to be beneficial for protecting against loss of brain tissue, specifically within the frontal, temporal, and parietal regions."

• "Those exercise programs that incorporated ∼ 170 min of exercise/weekly improved insulin sensitivity (≈ 85%) more than a program utilizing ∼ 115 min of exercise/weekly (≈ 40%), suggesting that exercise duration rather than intensity plays a role in improving insulin sensitivity."

• "The exercise training-induced reduction of inflammatory status contributes to improve the insulin signaling." Lower inflammation caused by exercise improves the binding and activation of insulin on its receptors on the surface of cells supposed to receive it.

Regarding the higher risk of development of dementia in people with insulin resistance and diabetes, an article explained that people with diabetes, especially uncontrolled diabetes, tend to have a "decline in glucose uptake [in the brain] with cognitive impairment and Alzheimer’s disease." Aerobic exercise improves glucose uptake across the blood-brain barrier, contributing to "increased brain volume and blood flow and a decreased risk for cognitive disorders."

Another study used intranasal insulin in study subjects, because this type of insulin can directly enter the central nervous system, and the dopamine levels in the brain helped increase insulin sensitivity in brain cell receptors, but insulin sensitivity was only enhanced in individuals who exercised as well as received intranasal insulin. This study showed that it's likely that exercise increased dopamine levels in the brain and increased insulin sensitivity in the brain of study subjects. Also, exercise increased insulin action in the right hippocampus, contributing to enhanced neural plasticity in the hippocampus of these individuals.

Increased insulin sensitivity in the brain was correlated to increased cellular respiration in skeletal muscle cells.

Insulin acts on the brain to control systemic metabolism and body weight. "Human brain imaging studies show that central insulin action affects region-specific activity and functional connectivity of the human brain with subsequent effects on cognition, eating behavior and metabolism. Specifically, central insulin action curbs food intake, improves mood and memory function", among other functions. "Disruption of insulin receptors in the brain results in obesity-associated insulin resistance." Therefore, exercise in enhancing insulin sensitivity and preventing and treating type 2 diabetes and prediabetes is of paramount importance.

It's essential to stay consistent with a continuous exercise regimen. A study mentions that "maintenance of glucose control and insulin sensitivity are maximized by physiologic adaptations that only occur with weeks, months, and years of exercise training."

An article mentioned in its key points that "in addition to the cardiovascular benefits, long-term exercise promotes healthier skeletal muscle, adipose tissue, and liver and pancreas function", and that "exercise programs for patients with type 2 diabetes should be of sufficient intensity and volume to maximize the metabolic benefit while avoiding injury and cardiovascular risk."

Last but not least, those people with diabetes with foot ulcers benefit from exercise "given the potential benefits of exercise on patient health and wellbeing." Studies encourage non-weight-bearing exercise as one of the ways to manage the treatment of diabetic foot ulcers. "Further research is required to better understand the relationship between exercise and healing of diabetic foot ulcers”.

The aforementioned benefits of exercise help shed light on a deeper level, beyond knowing that “the favorable effects of exercise training are limited not only to the prevention, but also to the control of the prognostic determinants of diabetes, such as the glycaemia, blood pressure, and lipid profile”, or "regular exercise produces health benefits beyond improvements in cardiovascular fitness. These include enhanced glycemic control, insulin signaling, and blood lipids, as well as reduced low-grade inflammation, improved vascular function, and weight loss." They show specific ways exercise helps people who want to prevent and treat diseases, and they also indicate the interconnection of all systems in the body and the increased need to see the human body and its functions as interconnected.

A woman wearing a continuous glucose monitor on a hike

Feel free to send me questions or comments, and let me know how you enjoyed this blog post.

To our health with more exercise,

Girlene

Works Cited

Colcombe, Stanley J., et al. ‘Aerobic Fitness Reduces Brain Tissue Loss in Aging Humans’. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, vol. 58, no. 2, Oxford University Press (OUP), Feb. 2003, pp. 176–180, https://doi.org10.1093/gerona/58.2.m176.

Erickson, K. I., et al. ‘Physical Activity Predicts Gray Matter Volume in Late Adulthood: The Cardiovascular Health Study’. Neurology, vol. 75, no. 16, Ovid Technologies (Wolters Kluwer Health), Oct. 2010, pp. 1415–1422, https://doi.org10.1212/WNL.0b013e3181f88359.

Iaccarino, Guido, et al. ‘Modulation of Insulin Sensitivity by Exercise Training: Implications for Cardiovascular Prevention’. Journal of Cardiovascular Translational Research, vol. 14, no. 2, Springer Science and Business Media LLC, Apr. 2021, pp. 256–270, https://doi.org10.1007/s12265-020-10057-w.

Kirwan, John P., Thomas P. J. Solomon, et al. ‘Effects of 7 Days of Exercise Training on Insulin Sensitivity and Responsiveness in Type 2 Diabetes Mellitus’. American Journal of Physiology. Endocrinology and Metabolism, vol. 297, no. 1, American Physiological Society, July 2009, pp. E151-6, https://doi.org10.1152/ajpendo.00210.2009.

Kirwan, John P., Jessica Sacks, et al. ‘The Essential Role of Exercise in the Management of Type 2 Diabetes’. Cleveland Clinic Journal of Medicine, vol. 84, no. 7 suppl 1, Cleveland Clinic Journal of Medicine, July 2017, pp. S15–S21, https://doi.org10.3949/ccjm.84.s1.03.

Kullmann, Stephanie. ‘Exercise Restores Brain Insulin Sensitivity in Sedentary Adults Who Are Overweight and Obese’. JCI Insight, vol. 7, 2022, https://doi.org10.1172/jci.insight.

Robinson, Matthew M., et al. ‘Increased Brain Glucose Uptake after 12 Weeks of Aerobic High-Intensity Interval Training in Young and Older Adults’. The Journal of Clinical Endocrinology and Metabolism, vol. 103, no. 1, The Endocrine Society, Jan. 2018, pp. 221–227, https://doi.org10.1210/jc.2017-01571.

Morica, M., and Melanie N. Haley. ‘Does Exercise Improve Healing of Diabetic Foot Ulcers? A Systematic Review’. Journal of Foot and Ankle Research, vol. 14, 119AD, https://doi.org10.1186/s13047-021-00456-w.