"My gf would kill me..."
Ah, running away from angry girlfreinds/ their dads/brothers/sensei's has kept me the lean, mean aiki machine I am today
Or:
Take the warm up (often actually body conditioning exercises) you do in your normal class and double all the number of reps. Throw in a few other exercises that you need/like, and heh presto, an hour long daily aiki work out.