I see many good suggestions from Christine and Harris. The possibilities are endless. One I didn’t see mentioned (or I just missed it!) is an agility ladder. There’s many good drills out there using that – you can really make it into a killer CV workout and, at the same time, work on agility, coordination, etc. My racquet sport clients love it – I have 70 year olds using it. You can get a decent one for a very reasonable price – Power Systems/Perform Better.