woman running

Exercise May Not Be Enough Against Diabetes

Even active young adults with type I diabetes can suffer poor muscle health, which can be devastating down the road.


Researchers from McMaster and York University have found that poor muscle health could be a complication of type I diabetes, even with young adults who regularly exercise.

The team studied muscle biopsies of individuals with or without type I diabetes, all of whom went over the 150 minutes-per-week exercise guideline, as recommended by Diabetes Canada.

Type I diabetes is characterized as an autoimmune condition in which the body’s immune system turns on itself. Specifically, the beta cells in the pancreas which produce insulin are attacked, leading to a shortage and difficulty with managing blood sugar levels.

For those with diabetes, the team found structural and functional deficiencies in their cellular power generators, otherwise known as mitochondria. These organelles act as power generators for cells by absorbing nutrients and creating energy-rich molecules for the cell.

Cardio-intensive activities such as cycling, running, and swimming boost mitochondria numbers in the muscle as cells demand more power. More and more glucose (sugar) is used up in the process, allowing muscle cells to power through while simultaneously helping to regulate blood sugar levels.

However, type I diabetes patients are up against an unexpected stumbling block.

Malfunctioning mitochondria threaten muscle health

Besides producing an insufficient amount of energy for the cells, the mitochondria in type I diabetes patients were also found to be releasing toxic byproducts related to cell damage.

“Skeletal muscle is our largest metabolic organ and is the primary tissue for clearing blood sugar after eating a meal, so we need to keep muscle as healthy as possible,” says Thomas Hawke of McMaster University.

“We believe these dysfunctional mitochondria are what’s causing the muscle to not use glucose properly and to also damage muscle cells in the process. We were surprised to see the muscles were this unhealthy in young adults with type I diabetes who were regularly active.”

Dysfunctional mitochondria can lead to a slowed metabolism and greater difficulty with controlling blood sugar levels. If left untreated, the development of disability could be accelerated.

“Now we know that even active people with diabetes have changes in their muscles that could impair their ability to manage blood sugar,” adds Hawke. “Knowing in the long term that this could contribute to faster development of disability, we can start to address it early on.”

The team noted that further research will be necessary to tell whether or not more rigorous exercise is needed to mitigate the issue. In the meantime, a revision of the 150-minutes-per-week guideline may be needed to keep those with type I diabetes in good health.

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Barry is a journalist, editor, and marketer for several media outlets including HeadStuff, The Media Editor, and Buttonmasher Magazine. He earned his Master of the Arts in Journalism from Dublin City University in 2017 and moved to Toronto to pursue a career in the media. Barry is passionate about communicating and debating culture, science, and politics and their collective global impact.