Tennis and racquetball, i've heard hard to do both. Having moved from rather hard style karate, into not just Aikido, but Ki Society Aikido I know you will have advantage...but if I take it correctly previous practice was Ju-Jitsu then disadvantage will be need to go slower than perhaps you wish so as to avoid injuring unwitting partner. Go slow, more flow, and as The Founder Master Uyeshiba emphasized, Aikido is Love, to find and give "Abundant Peace". Good to know how to separate muscle/tendon/joint in nikyo, very good to know how to bring to ground or submission using nikyo w/o maiming.
do not try to spork the post, for that is impossible, only realize there is no post to spork