Honestly, I do not find this odd that a 50 year old can do this. My friend ran 2:37 as a gimpy 50 year old. He simply trained as he knew he had to. If you have the mind and experience to put in the training you will. This is the main ingredient. You have to justify the means in your head to do it. If you have the will to train you will. It is all about laying it on the table. You will sacrifice and you will overcome.
If you know you can run miles you will suffer. There is no easy way to compete well. Obstacles are a weekly if not daily occurence. It's like leaning into the wind at full speed and saying don't spare the jalapenos. You take chances. Every week you have to reaffirm why your doing something. Personally, I will tell runners I am training to beat them. Your going to have to PR that day to beat me. I want people to succeed. I am going to train 80 miles a week this summer to break 2:50 so bring your A-game. By-the-way, training runs don't count. I'm going to pour everything into the hopper over the next 4 months to make sure I'm there.
I read this guys commitment and embrace it. Train like you mean it. Train beyond want you want to do. Of course it's difficult. I've had the pleasure as many of here have of seeing gifted athletes take charge of their own results. I never understood how others could train beyond me and I could sit back and wonder how I could somehow do less and keep pace.
Run. If all else doesn't happen …..run. I didn't sleep , I didn't eat well, I didn't stretch enough…blah…blah… blah. Get the work done. You don't see these guys complaining.
Pack a lunch.