What exercises are good for canoeing?

I’m going canoeing for three weeks soon apart from going on the rowing machine what exercises shall i do? I’m trying to improve my general fitness as well as my arm strength

The rowing machine probably won’t help as much as you think. It’s great for general conditioning, but rowing and canoeing use different muscle groups because the seating position is completely different. Rowing will work your back muscles, while canoeing will work your abs more. Either one, if done correctly (and that’s a big "if"), does not require a lot of arm strength. As for specific exercises, nothing could beat actually practicing canoeing itself. Otherwise, situps and crunches to work the abs, and then some other exercise for general fitness, which could be the rowing machine, but could also be running, swimming, or anything else.