TORONTO — Automated insulin delivery (AID) systems have revolutionized how people with type 1 diabetes (T1D) manage their glucose levels throughout the day. This technology is also having a big impact on competitive sports.

“We now see athletes on insulin competing at the highest level — in the NFL [National Football League], the NBA [National Basketball Association], track and field, cross-country, and every sport imaginable,” said Michael C. Riddell, PhD, professor of kinesiology and health science at York University in Toronto, during a presentation at the Diabetes Canada and Canadian Society of Endocrinology and Metabolism (CSEM) Professional Conference 2025.

While this technology has been around for a while, earlier versions were challenging to use. “You were literally wired up to the technology,” he said. “It was connected with a physical tail, so you had difficulty doing sports.” Riddell also has T1D, as do his son and mother-in-law.

As AID systems have advanced, he said, “You see more people competing at the Olympics and on the international stage with this disease.”

Exercise Presents Challenges

During physical activity, muscles need glucose to function properly. The more intense the activity, the greater the need. When an elite athlete, such as a cross-country skier, undergoes a PET scan immediately after a race, “you can see glucose uptake into all the working muscles at a much higher rate after exercise, independent of the insulin signal,” said Riddell.

Because of the jump in glucose use during intense exercise, low blood sugar is a concern for elite athletes. “Hypoglycemia typically doesn’t occur during really short bursts of intense activity,” he said, “but in a race that might last 2 hours, glucose utilization gets greater over time.”

For athletes, hypoglycemia can mean having to drop out of a race or undergoing urgent medical care. Plus, “there’s no stopping to treat low blood sugar when you’re on a bike,” said Riddell, so endurance athletes tend to “err on the side of hyperglycemia.”

For elite athletes with T1D, nocturnal hypoglycemia is also an issue, “as they’re trying to replenish the glycogen that they’ve used during that race,” he said. However, “with a continuous glucose monitor [CGM] and with some optimization of nutrition, they are seeing improvements” in reducing hypoglycemia after the race.

Improving Glucose Regulation

Closed-loop AID systems, which use an algorithm to adjust the delivery of insulin based on readings from a CGM, have made it much easier for elite athletes with T1D to compete.

Riddell and his colleague documented a case study in 2021, published in Diabetes, Obesity and Metabolism, of a cyclist with T1D who rode 6000 km across Canada in under 2 weeks while using an AID system. The cyclist “could keep his hands on the bike’s handlebars and not worry about stopping, checking, and administering insulin,” said Riddell.

Since then, AID systems have advanced even further. “This technology is not perfect,” he acknowledged, “but it does help, particularly with nocturnal hypoglycemia.”

To assist elite athletes with T1D in competing, Riddell and his colleagues published a position statement in Diabetologia in 2025 on best practices for the use of AID systems during exercise. The statement includes diagrams outlining how best to use different AID systems for planned and unplanned exercise.

Despite recent advances in technology, some AID systems manage glucose levels too aggressively during exercise, he noted, “and we still need to be cautious about that,” he said.

Barriers to Use

Alanna Weisman, MD, PhD, assistant professor of medicine at the University of Toronto, Toronto, pointed out in a separate presentation the importance of AID systems, not just for elite athletes but for anyone with T1D.She noted that the Diabetes Canada Clinical Practice Guidelines strongly recommend that AID should be used in all patients with T1D “to improve a number of outcomes.”

Despite this recommendation, barriers to accessing this technology remain. In an unpublished review presented at the conference, Weisman and her colleagues looked at 226 studies examining these barriers. The most common ones were financial concerns, systemic and structural racism, factors related to the clinic or healthcare providers, physical aspects of wearing devices, and older age.

Physical aspects “include things like discomfort from wearing devices, interference with activities or sports, or issues with skin or attachment points,” she said.

This finding fits with research presented by Riddell at the conference, published in 2025 in Clinical Diabetes, which found that among 102 patients with T1D who exercised, 75% reported using an AID system. Over half reported removing their pump for exercise at least some of the time.

In addition, many were not following clinical recommendations on the use of AID systems for exercise — only 27% reported adjusting the basal insulin 60-90 minutes before exercise, and 51% reduced their pre-exercise meal bolus.

“So, we’ve got work to do,” said Riddell.

Riddell reported receiving funding or other support from Dexcom, Insulet Canada, Novo Nordisk, and Zucara Therapeutics. Weisman reported receiving funding or speaker honoraria from Breakthrough T1D, Canadian Institutes of Health Research, CPD Network, Diabetes Canada, Diabetes Care Community, Noble Insights, and Ontario Health.

Shawn Radcliffe is a freelance health and science journalist based in Ontario, with more than 15 years of experience writing about general health, medical research, mental health, and other topics for print and online publications. He previously performed laboratory and clinical research and research administration at universities in Philadelphia and Portland, Oregon. He has a master’s degree in science education from Drexel University, Philadelphia.