When you exercise for a long period of time your brain makes chemicals called?

When you exercise for a long period of time, your brain produces chemicals called endorphins, which act as natural painkillers and mood elevators. Additionally, exercise increases the production of neurotransmitters like serotonin and dopamine, which can enhance mood and reduce feelings of anxiety and depression. This combination of chemicals contributes to the "runner's high" often experienced during prolonged physical activity.