Many marathon runners know the boost that can come from popping a mid-race energy gel. (Mmmm, calorie-rich goop.) But according to new research published in Science Advances, when it comes to endurance events, there’s a limit to how much energy the human body can draw from breaking down, or metabolizing, food. That metabolic limit depends on how long whatever tortu… — err, event you’re enduring lasts. But importantly, after a certain point in time, it plateaus, suggesting humans have a universal cap for how much energy their bodies can absorb.