Z: Whey protein is always a favorite in the bodybuilding world. For starters in protein supplementation the combination of Arginine/Ornithine/Lysine will increase male hormones and particularly Human Growth Hormone (HGH) and fuel muscle metabolism.

Consider supplementing DHEA to recover the slowly fading hormone levels with aging. Boosting Testosterone in particular can be achieved by supplementing (along w/ the DHEA) D-Aspartic Acid. Boosting these hormones causes an "androgenic" or "building up" effect. There are also a number of herbs that increase T like Tribulus, Horny Goat Weed, Maca, LongJax, Muira Puma, and lastly and most importantly Stinging Nettles or Avena Sativa as these protect the prostate gland from inflammation due to unused Testosterone.

As for diet, be sure your paleo is replete with high quality meat. Most beneficial and eaten occasionally is organ meats (big favorite in the paleo diet) especially raw or cooked Calf or Chicken Liver. Liver is considered a nutrient dense "superfood".

Protein, protein, protein! :)

Since it's difficult to eat enough protein every day to help build muscle mass, most (myself included) use a protein powder and make shakes--3 shakes per day.

For promoting muscle mass, protein shakes are best consumed immediately after your workouts. I bring one that I already mixed at home to the gym with me and drink it on the way home from the gym.

I use whey protein powder. You can buy it in bulk online. It's more cost effective to buy a 5lb+ lb container. It comes in several flavors. I prefer the chocolate, but I also buy a smaller container of vanilla that's great for adding to fresh fruit for juicing.

I have a Nutribullet juicer and add bananas, strawberries, blueberries, raspberries, apple, etc. then add a scoop of the vanilla protein powder for a nutrition-packed 'dessert' smoothie.

Good stuff! :)