No, it's not that.
On the Casino last night they reacted to a clip in which Amish explains that her and Ian go to the gym together, and when they're lifting weights together (imagine them lifting free weights or doing bench/squats/deadlifts) Ian will look at the amount of weight Anisa is lifting will say, "that's good enough for me."
In other words, Ian is probably benching so little weight that he's only getting a cardio workout, not even building up his muscle endurance, let alone gaining lean mass.
I've heard that lifting girlishly small amounts of weight at the gym is a fetish of some kind, but I think Ian is just that retarded.