What Research Shows About Type 1 Diabetes and Exercise Performance

Researchers recently conducted a systematic review—a comprehensive look at published studies—to understand how Type 1 diabetes affects exercise performance and fitness. They searched seven scientific databases and identified 28 studies that directly compared exercise ability in people with and without Type 1 diabetes.

The review focused on three types of exercise: aerobic (sustained, steady-paced activity like running or cycling), anaerobic (short bursts of intense effort), and skill-based exercise. Researchers also looked for clues about the biological mechanisms—the 'why'—behind any differences they found.

The vast majority of studies in the review (25 out of 28) examined aerobic exercise performance. These studies used standard tests like timed runs, cycling tests to exhaustion, and VO₂peak measurements, which gauge how efficiently the body uses oxygen during hard exercise.

About 88% of these aerobic studies reported lower aerobic performance in people with Type 1 diabetes compared to those without. The researchers noted that cardiovascular health, how blood circulates, and metabolic factors (how the body processes energy) may play a role in these differences.

Only five studies examined anaerobic performance—the kind of explosive strength and power needed for sprinting or heavy lifting. Of these, 60% found lower performance in people with Type 1 diabetes.

The researchers suggested that differences in mitochondrial function (the energy-producing structures in cells) might explain some of these findings. However, because so few studies examined this area, conclusions remain tentative.

The review's authors were transparent about a crucial limitation: they rated the overall quality of evidence as 'very low' using an established scientific tool called GRADE. This means the existing studies have various limitations that make it hard to draw firm, universal conclusions.

Many factors influence exercise performance in Type 1 diabetes—including blood sugar management during activity, overall fitness level, how long someone has had diabetes, and individual genetic differences. Future research with larger, well-controlled studies will be needed to clarify which factors matter most and how they interact.

While current evidence suggests aerobic capacity may be reduced on average in Type 1 diabetes, this is a population-level observation. Individual experiences vary widely. Many people with Type 1 diabetes achieve high levels of athletic performance through proper management, training, and support.

If you have Type 1 diabetes and questions about exercise capacity or training, discuss your goals with your diabetes care team. They can help you manage blood glucose before, during, and after activity—a key factor in how well you perform and how you feel.

Source: Canadian journal of diabetes. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.