I'm 46 and I can't say enough about the importance of bringing up your growth hormone levels when it comes to strength and recovery. At our age the pituiatary gland doesn't produce squat in terms of gh.
I recommend you take some form of androgen and pharma grade hgh or ghrp2 with cjc no dac.
100mcg ghrp2 with 100mcg cjc no dac 3x/day subcutaneously will produce approximately 2ius of hgh. The hgh comes from your own piruitaty gland so it contains all 5 isoforms of hgh. Synthetic hgh is merely one form of hgh. Your own hgh is superior as it will not lead to antibody production. Also, last year the Chinese govt closed down non GMP hgh plants so most all Chinese generic hgh is currently bunk.
In terms of what androgen to take, I myself use testosterone. I have yet to try the various SARMs for androgen support. The other mods here know a lot about those products do they can help you there.