Short-Term Metformin Use in Young, Healthy Adults: Impacts on Exercise Capacity

This study examines whether taking metformin — the most commonly prescribed blood sugar-lowering medication for type 2 diabetes — for a short period reduces exercise capacity in young, healthy adults, particularly the ability to sustain high-intensity effort and the point at which lactate starts to build up in the blood. Metformin works by altering how cells produce energy in a way that resembles exercise, and there is concern it may compete with or limit the body's response to vigorous exercise. Adults aged 18–30 who are recreationally active (exercising 3+ days per week), have a BMI under 30, have never taken metformin, and have no history of metabolic or cardiovascular disease may be eligible. Participation involves 5 exercise tests on a stationary bike, body composition testing, a short course of metformin and placebo capsules (taken in a crossover design), and food and symptom logs. This summary was generated with AI assistance and is intended to help patients understand the study in plain language.