Re: Does one's size or weight affect one's Aikido?
In the course of my aikido career, I have gained a lot of weight and then lost it again. I think it was harder for others to move me when I weighed more, but also harder for me to move myself. My ukemi especially suffered with the extra weight - it just seemed like I was hitting the mat a lot harder, and I wasn't as flexible.
If the extra weight is muscle (without being so bulky that it limits flexibility), then the advantage gained in power might offset the disadvantage of innertia. I can't speak to that point, though.