You'll find this sort of thread all over the forum. If you were already doing the rowing before joining WW you can't count it! You only get AP when you do over and above your normal activity rate!
I kiss goodbye to nearly 90 a week lol
But what you get depends on whether you rate your activity as high, moderate or low and what you weigh. (The more you weigh, the harder your body works so you get more!).
I would get 9 for every 30 mins I do on the xtrainer but I was already doing it before joining so it's not counted! I can't count any of my activites at the gym, unless I do more!!