I'm only 48-and-three-quarters so this may just go horribly wrong in just over a year. But here's what works well for me. It's called "Easy Strength" and based on what the Russians found actually worked for athletes (not bodybuilders) over several decades.
1. Do some light exercises every day taking all your joints through a full range of movement. This could be a good warmup, or at another time of day.
2. Pick a handful of exercises that require strength. Do them 5x per week
- no more than 10 reps per day. 2x5, 5-3-2, 3x3, that kind of thing
- start light. Get used to doing it daily. There should be NO fatigue; if there is, do it lighter.
- On days where the bar feels light, add some weight
Good routines include
- deadlift and press (that's the Barry Ross / Allyson Felix routine) - needs a big bar
- power cleans or romanians + front squats + overhead press + pullups - all works with a medium bar
- single leg deadlifts + single leg squats + pullups + one arm press. Works with a pair of dumbells
Do not bother worrying about when to time your lifts around your sessions. The power of the "daily habit" is far more significant. You promise yourself to show up; you do not promise to lift any particular weight. On the days when your legs are tired from training, a few light reps is a great tonic.
Get over to the Dan John forum and you will find a bunch of guys discussing how to combine strength with growing old, running and many other sports. They are unfailingly polite and helpful, unlike LRC sometimes.
http://www.davedraper.com/fusionbb/showforum.php?fid/73/
Good luck!