I just started training my arms again. Over the years I have been building gym equipment and using equipment like big angle grinders keeps the forearms up. I can grow my arms faster now than when I was in my prime. The trouble is when I use the really heavy weights my connective tissue hurts. A pity because I could easily get them bigger than ever even at 70. I am more interested in photography than gyms and bodybuilding. The desire to get bigger is still there but the motivation to do so is lacking. Doing squats or heavy leg presses is not something I get around to doing. I do go for long hikes carrying 20kg of camera equipment with me. Keeps my calves at over 17 1/2 inches without training them.