Why does exercise make us tired? A new theory says it's not just about sore muscles or low energy. Instead, fatigue might be your brain realizing it can’t keep the body in balance. When predictions about heart rate, temperature, or effort don’t match reality, your brain sends a warning signal. That sensation of tiredness could be less about limits... and more about uncertainty. Tap the link in our bio for the research. ✍️ : sweat_science #getoutside #outsidemagazine #sweatscience