I’ve been training to run the New York City Marathon on Sunday. At age 70, even in the best conditions, it would be a slog over 26.2 miles, longer than five hours. That is less a time for a race than a recipe for short ribs.

There is no such thing as an athlete aging gracefully, my physical therapist has long reminded me. Last week, I aggravated a hip injury. It’s not the finish I’m worried about now. I may not even reach the start.

Either way, this was likely to be my last marathon. I’m old and slow, increasingly broken down despite diligent strength training. These days, I’m running nearly two hours behind my personal best of 3 hours 57 minutes. My finishing time for a half marathon in September was listed as “ticketed for loitering.”

I feel enormously frustrated at possibly having to drop out of New York at the last minute after months of training. But I’m also weirdly amused at the arbitrary timing of the injury — a mile into an easy five-mile run — and curiously accepting of whatever happens on Sunday.

Perhaps because I’m a reporter, I view the setback with some detachment. I turned 70 with a dispassionate, almost clinical, interest in what happens next. It is an age when careers have been made, children have grown, retirement beckons to those who haven’t yet embraced it. Our athletic careers have been shelved in dusty remembrance. Our bodies have weakened. But the thrill of unexpected possibility still awaits.