GLP-1 Use in Active Populations and Potential Effects on Glycogen Availability, Appetite, and Training Outcomes

Glucagon-like peptide-1 (GLP-1) receptor agonists have gained widespread clinical use for the management of type 2 diabetes and obesity due to their effects on glycemic control, appetite suppression, and weight loss. These agents prolong the short half-life of endogenous GLP-1, resulting in enhanced insulin secretion, reduced glucagon release, delayed gastric emptying, and altered central appetite regulation. While the metabolic and therapeutic benefits of GLP-1 receptor agonists are well established in clinical populations, their implications for athletic performance and recovery remain poorly understood. Emerging evidence suggests that GLP-1 receptor agonists may influence energy intake, substrate availability, and hormonal signaling related to satiety, raising concerns regarding adequate caloric and carbohydrate consumption in physically active individuals. Reduced carbohydrate intake may limit muscle glycogen availability, potentially impairing training quality, recovery, and overall performance. Comparisons with other substances known to alter metabolism in athletes, such as caffeine, clenbuterol, and thyroid hormones, highlight key differences in mechanisms and potential risks. Additionally, the growing off-label use of GLP-1 receptor agonists has introduced ethical, regulatory, and access-related challenges, particularly following their inclusion in the World Anti-Doping Agency monitoring program. Given the limited data available in athletic populations, further research is needed to evaluate the safety, metabolic consequences, and performance-related effects of GLP-1 receptor agonist use in high-performing individuals.