Play it safe or push yourself?

Earlier today I went out for a 5 mile tempo run. My goal was to run it at a 9:10 pace and over the course of the 5 miles I ended up averaging 9:02. I realized during the run that each time I set out with a goal in mind, it's usually a relatively safe goal that I would tend to always meet and even exceed. Case in point today, my first mile was 9:08, then each one after was just a little faster, ending the last two miles below 9. How did it feel? Well, it felt pretty good, not seriously hard and not seriously easy. Two weeks ago I ran my last tempo run with a goal of 9:20 and I ended up averaging 9:15. I tend to do this a lot, I pad my running goals to allow myself the opportunity to exceed my expectations. I'm not sure if this is the best approach, and I didn't even realize I was doing it until today, but I'm pretty convinced that this is my tendency. I also noticed this yesterday while climbing at the gym. I tend to pick easier climbs I know I won't have any trouble with, or I'll go in the opposite extreme and get on something I know I can't climb, so there is no pressure to succeed. With me finally realizing what I do to ensure I succeed, I'm not sure how I want to handle it. I definitely think that I'm doing really well with the running the way I manage my goals, but sometimes I wonder if I could have excelled even more had I pushed myself further. With climbing though, I think that I'm holding myself back from excelling because of this fear of failure. I try to embrace the fear of failure to some degree, because it was the fear of not being able to run a half marathon that pushed me to lose 70lbs. I wouldn't never have gotten here had it not been for that fear. I can see positives with it, but there are some things where this fear holds me back. Definitely something I need to continue to watch and think about for the future.