After I hurt my Achilles (I'm 36 as well) I did away with jogging and started doing LOTS of calf and Achilles stretches. That seems to have kept the tendinitis at bay.
I try and get to the gym and use the elliptical but easier said than done.
(4) Volkl PB 10 Mids
Babolat Tonic+ 16/Babolat RPM Team 17 @ 51 lbs