[GratefulCitizen]

Talking with the old man again about running, he's been competing now for 57 years.
He just set an American record for the 70-74 age range in the 10k, 40:14 (that's about 6:29 per mile).

He's been gradually healing from some injuries and is still improving, and thinks he may be able to shave up to a minute off of that time in top shape.
Realized that some of his rehab/recovery principles may apply to those who are nursing injuries, are older, or are carrying wear and tear towards the end of a physically demanding career.

After picking his brain, here's what I got:

Stay away from too much intense (fast) training.
One intense day per week at most, not too intense, and only after you're in reasonable shape.

Focus on making gradual gains in volume (weekly mileage).
High frequency training is better, i.e.: it's better to train 6 days per week for shorter runs than 3 days per week for longer runs.

As you get older, the mind will easily push the body past the breaking point.
The gifts of youth are no longer available to forgive the error with quick healing and recovery.

There it is:
Limited intensity, high frequency, focus on volume.

HTH.