As an aside, as you get older strength training is highly recommended even (especially) if you're an endurance athlete, even if you never did much strength training before.

Hit the big muscles groups to stimulate hormone production (to offset natural aging decline)... that's important because the hormones in your system keep all the little muscles from atrophy (the ones that you don't even realize you have until you injure them).

Also do some focused work on injury-prone areas like rotator cuffs, hammies, etc.

I've had several friends with ruptured achilles, older guys play hoops, football on thanksgiving, etc. Calf lifts are important for that reason, but it's also one of the big muscles groups that you should hit for overall hormone production.

And core. Come up with a comprehensive back-safe core routine, especially in our job. You can do it as infrequently as once a week and it should go a long ways to prevent back injury.

Stretching and functional training is also good. You'll sleep better if you stretch before you get in bed after a long day in an airplane seat.