For what it’s worth, the T-ransformation actually had a lot of people in their mid-to-late 30s and a few that were almost 50. Not all of them actually finished the challenge though. So it’s not like it was “just” a younger lifter’s game. I also have a feeling some older lifters aren’t necessarily comfortable posting shirtless pics on the Internet, so that’s a separate issue.
Rumor has it there may be a more organized, somewhat more “official” T-ransformation coming around in 2018, but if you want to put together your own thing, go for it for sure.
Nothing wrong with that in general. And, while it’s not necessarily a strict “challenge”, we do have the Photo/Video Check-ins every February 1 and August 1 if you want a general target to aim for.