In general, hiking is more demanding than running because it typically involves carrying a backpack and walking uphill for extended periods of time.
If you’re relatively fit, you may find that running is actually harder than hiking. This is because running puts more stress on your body, particularly your joints and muscles. On the other hand, if you’re not very fit, hiking may be more difficult since it requires more endurance.
Ultimately, the best way to determine which activity is harder for you is to try both and see how you feel. If you enjoy both activities, there’s no reason why you can’t do both regularly. However, if you find that one is significantly more difficult than the other, you may want to stick to the activity that you enjoy more.