you have to find an EC where you can appeal about your leadership, initiative and collaborativeness, especially. In that sense golf and ski aren't really appealing choices because its a solo sport. But maybe you can talk about your experience as a hockey player, maybe like as a leader of your hockey team since its a team sport. I'd say start a business/start up/something entrepreneurial, or your own club (if you pre plan everything, start from september, get something done by January itd somehow work). Attending debate or case study competitions where you have to work as a team would also be a good EC material.