Push it to the Limit: I work hard, so what

One thing i can pride myself on is that I am a hard worker. 
Some of my friends have a misconception that at work i am not a hard worker and instead that i am hardly working. I think i have done well for myself and that other people do think that i am a good worker too, but do I really push myself?

However, working hard is not the same as Pushing yourself. I was asked recently if I push myself and I couldn't answer. How do you push yourself?

Five extra push ups.

Achieving ambitious targets.

Setting unrealistic goals.

Putting yourself in an uncomfortable position.

Being outside of your comfort zone.

Maybe it is all the above, I just couldn't answer and then I struggled to think of any example to get close. In my mind all of the above can be achieved by working hard and therefore you don't need to push yourself. This is the case in the first two points but the last three do then need you to PUSH YOURSELF.

A bit of stress may come about, some nerves too but the end result will be pride, relief and happiness. I truly believe this and I will now try to push myself at work and at home. How? I don't know yet but if anyone wants to set me a challenge then please do let me know.