Exercise and insulin sensitivity: a review of human training evidence

Objective: To review human evidence on the relationship between exercise and insulin sensitivity. This article synthesized randomized trials and training studies evaluating how aerobic and mixed exercise programs affect glucose disposal, insulin action, and cardiometabolic risk markers. The evidence consistently showed that regular exercise improves insulin sensitivity, particularly in sedentary individuals, those with overweight or metabolic dysfunction, and participants who adhere to sufficient intensity and volume. Benefits were seen across multiple training modalities, though aerobic exercise had the most reproducible effect on glycemic control. The review also noted that baseline fitness, body composition, and energy balance influence response magnitude, making one-size-fits-all recommendations overly simplistic. Exercise was framed as a foundational intervention rather than an adjunctive measure because of its broad physiologic reach and low cost. The authors highlighted that the strongest real-world challenge is adherence, not biologic plausibility. Overall, the review supports structured physical activity as a robust tool for improving insulin responsiveness.