If you want to get a good time, ask @JakRunner1 (last year’s old guy on the Big Marathon Challenge), not me! He really is quick.
In addition, keep running for the sheer pleasure of it, as well as for the sense of achievement, and the feelings of health, well-being and optimism that come with physical exertion.
Soak up and enjoy all the admiration and praise you’ll receive. I’m often told, “I only hope I’ll be able to run at all at your age,” or “I’ll be pleased if I can walk to the bus stop in my 70s!”
You can be assured that running when you’re older ensured you’ll look fitter than most people half your age. It’s all marvelous for morale!
Finally, and this is really advice to myself, accept that you are not going to be as fast as you were 10 years ago, let alone 25!