I'm in my 30s and am far stronger and bigger than i was in my 20s. Stop training like a bunch of fukkin' twinks.
It may not be just their training. There's the nutrition side of the house, too. As I mentioned elsewhere, too many would-be bodybuilders have abysmal diets and expect supplements to make up for their poor eating practices.
Then, when they run out of money and end up doing what they should have done from the get-go, FIXING THEIR DIETS (and finally getting some decent results), they whine about how worthless supplements are.
Again, I don't know who came up with the dumb idea that the party's over at 30, with regards to gaining size and strength. But, they need to get a grip.