The beauty of running wrote:
My answer:
Anything faster than you've run before.
And then, that soon becomes "not so fast" as you aim for something better.
That's the beauty of running that is so often missed. If you know someone running in NYC marathon runs a PR by 10 minutes, they did a great job, no?
Unfortunately, many (in media and elsewhere) will treat the race as having one male winner and one female winner, with tens of thousands therefore being "losers". (Well, as I type that, I also lament the type of coverage where it's all just a parade or cultural event, who cares what you run..). Worse yet, if you don't sent the WR, you've "failed".
So, look. Start running. Get faster than you used to be. Then, aim to get better than that.
Jerry Seinfeld: "A marathon? What's to see? A guy from Kenya, a woman from Norway, and twenty thousand losers."