Ergogenic properties of metformin in simulated high altitude

Summary Metformin augments glucose/glycogen regulation and may acutely promote fatigue resistance during high‐intensity exercise. In hypobaric environments, such as high altitude, the important contribution of carbohydrates to physiological function is accentuated as glucose/glycogen dependence is increased. Because hypoxia/hypobaria decreases insulin sensitivity, replenishing skeletal muscle glycogen in high altitude becomes challenging and subsequent physical performance may be compromised. We hypothesized that in conditions where glycogen repletion was critical to physical outcomes, metformin would attenuate hypoxia‐mediated decrements in exercise performance. On three separate randomly ordered occasions, 13 healthy men performed glycogen‐depleting exercise and ingested a low‐carbohydrate dinner (1200 kcals,