Not necessarily as much as you might think. It will differ for each person. You might not even realize that you are being an inspiration.Everything that you do can be inspiring to the right person.
Did you share a recipe that was healthy? Someone might have seen it and decide that looks good and takes a step to cook a meal at home instead of going out. Guess what! You just inspired someone.
Did you post a photo of yourself at the gym? Someone might have seen it and decided they were going to do something active. Guess what! You just inspired someone.
Did you do something that pushed you outside of your comfort zone? Did you shout it to the roof tops when you finished? Someone probably saw it and probably decided to do something else to step outside of their comfort zone. Guess what! You just inspired someone.
I know that running a marathon or an ultra marathon is inspiring. So is running a 5k when you couldn’t run 30 seconds a year ago. You know what else is inspiring? Walking a 5k even when you are worried people might be looking at you.
Anything you do that pushes you is inspiring. Remember that what you are doing could be inspiring someone, just as you are being inspired by others.