this is just my opinion but save most of your money and get a medicin ball and a few bungy chords. try running with a partner and toss the ball back and forth theres a ton of other things you can do with it. the bungy chords are for tying yourself to something and trying to run against them.

but thats just me. you could also go camping any where above 12k feet for a couple weeks and trying to run up and down the hills.