You have probably been told that walking or cycling helps keep blood sugar in check. Most people hear that advice, nod, and start their day. The reason it actually works has been harder to pin down.
Researchers at the University of Oklahoma and the Pennington Biomedical Research Center report their findings in Nature Communications. They identified a protein called Miro1 that builds up in the muscles of people with type 2 diabetes.
When they removed the protein in lab models, the muscle cells responded to insulin again.
Insulin resistance sits at the center of type 2 diabetes. The body still makes insulin, but muscles stop listening to it, and sugar lingers in the blood instead of being burned for energy. Why that happens at the molecular level has been a long-standing puzzle.
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What the team found inside muscle cells
Miro1 sits on the outer surface of mitochondria, the tiny power plants inside cells. The team checked Miro1 in three places. They looked at isolated cells, animal models, and muscle samples from people with type 2 diabetes.
In every setting, more Miro1 meant worse insulin response.
Senior author John P. Kirwan leads the OU Health Harold Hamm Diabetes Center at the University of Oklahoma. "Insulin resistance in muscle is at the heart of Type 2 diabetes, and its molecular causes have remained frustratingly unclear," he said in a statement.
How regular exercise lowered the protein
The researchers also ran a small randomized trial in adults with type 2 diabetes and obesity. One group got standard medical care. The other followed a 12-week program of moderate-intensity treadmill walking or jogging, 5 days a week.
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In the exercise group, muscle Miro1 fell sharply. Insulin sensitivity improved, and the muscles produced energy more efficiently. The sedentary group showed the opposite pattern, with Miro1 continuing to climb.
The human trial was small, with 24 participants, so the clinical finding rests on a modest sample. The strongest evidence that Miro1 drives insulin resistance comes from the cell and animal work, where the researchers could switch the protein off directly.
Why this matters for people with the disease
Type 2 diabetes affects about 40.1 million Americans, roughly 1 in 8, and another 115.2 million adults have prediabetes, according to the CDC. Exercise is one of the first things doctors recommend, alongside diet changes and medication.
The authors suggest that Miro1 could eventually serve as a drug target. That would matter for the many people with type 2 diabetes who cannot exercise enough to see the full benefit, whether because of joint pain, heart problems or time.
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A targeted drug is years away. Any Miro1 therapy would need to show it is safe and effective in much larger trials before it reached patients.
For now, the standard recommendation stands. People with type 2 diabetes or prediabetes should talk to their doctor about an exercise plan that fits their health.
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This article is made and published by Aksel Kryhlmand, who may have used AI in the preparation.