system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why does working out helps so much with mental health?

I have OCD and working out ALWAYS makes me feel better whenever I have spikes. How does that work?
gpt
Exercise had been shown in many studies to promote the production of serotonin and dopamine, the two neurotransmitters responsible for making you feel good. Evolution has selected for physical activity to make us feel good, making it more likely for us to be physically active, which promotes our physical health. This is called a positive feedback loop, and is an example of one of the many, many positive feedback loops employed in your biochemistry.