Please answer: it's so FREAKING IMPORTANT...you see it's a bit scary...but requirements to be answered!?

can you masterbate if your doing pull-ups using bar to the chin exercises? my friend is worried that she have accidentally been doing it. she strains her muscles as much as possible while limp from a bar, and at alike time works her abs by pulling her knees up to her chin and back down similar to crunches. so is it possible to get one and the same sensation "down there" by working your muscles to the max? is that a form of masterbating? if ti's not masterbating what could it be?
please help us out!
Answers:

My length comes once every 3 or 4 months. Is this normal?

Well, no AND yes. Women's orgasm function is different for respectively woman, and this function is more or less fixed. Some women can't own an orgasm at all unless they are touched right on it. The other closing of the spectrum is women who orgasm very smoothly, so easily that they do it by stroke of luck. This may be your friend. Actually lots of women like this orgasm involuntarily when doing chin-ups! This is NOT a technique to masturbate, it's in recent times how she is built. And most women will not get matching result.
It sounds like perchance she feels guilty. Well she shouldn't, it's not intentional and at hand's nothing wrong near it.