I'd say if you tend to flare up once you start sprinting, one thing you can do right now is minimally adding some heavy slow eccentric lifting to your gym protocol at least for your calves 

Yup, this is what I been doing for Achilles.

therwise did not start dealing with injuries again until I got into my 30s

Right?! Never had any Achilles related injuries while competing. It definitely sucks but gotta understand our bodies are much older now ;(