I like sprinting a couple times up our hill, ca 10s each, 4-6 times. It’s full out, and when I‘m untrained (like now), I‘m quite exhausted afterwards.

But the dopamine boost I get from this is immense. It lasts 24-48h. I‘m in a general good mood for this period. Sometimes, a little more competitive than normal - that’s a downside.

Normal jogging or long walks don’t have this effect, at all.

A long race will do it just fine. AKA Runner's High.

I also do hill sprints. I try to do one [HIIT] workout a week and also some longer runs.

Hill sprints tend to be safer then sprinting on flat surfaces. Last time I did my HIIT sprinting on level ground my knee didn't really like that at all. A stationary bike (like the "assault bike") is even safer. Or you can just do burpies. People who don't run and haven't sprinted in a long time shouldn't just jump into sprinting.