Mass gain figures

Hi folks.
Got two stories here that made me intrigued. Wanna hear your opinions about them:

  • A friend of mine is going through a diet program that includes mainly aerobic training. This guy weighs 220 lbs. 5’11", about 20% fat, and in the age of 45. In the last few months he’s going through a long plateau, so the folks there measured him (don’t know how), and told him that he had gained lean mass of 9 lbs. in the last 2 months (without having his weight changed).
  • A guy in another forum I visit told there that after a change in his workout regime, he gained 33 lbs. of bodyweight in four months. He had been about 18% fat before, and stayed the same, so I figured he had gained about 24 lbs. lean mass.

So, does any of these stories make sense? What are reasonable figures of mass gain?

D.

I would guess disparities in BF analysis. Those figures are so easily skewed.

Well I guessed this was the answer - so what are reasonable figures for LBM gain?