I got my first yak last year, a used 10' pescador, and just kind of puttered around an fished in it a bit. I sold it last fall and bought a 12" clone of the Scrambler XT because I wanted something a little better for going out into the big water when I came down there. I've been trying to get into shape for coming down there so the last couple weeks I've been trying to build up for some heavier paddling. Last night I went out on our local lake and paddled pretty hard for 3 miles straight, half of which was directly into a 10mph head wind. I averaged about 4mph with a top speed of 4.8 for the trip, via a jogging app on my phone. I expected my arms and shoulders to be killing me today, but they aren't. I feel like like I've used them, but they aren't hurting at all. My legs however feel like I've run a marathon. Why do they hurt and my arms don't. Am I doing something wrong?