Try This for Cardio

Bigger Stronger Leaner Powerlifting & Strength Sports
1

prowler sled hell (simple conditioning work outs for football) - YouTube

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I threw up, just a little

3

its not that bad once you get used to it. I was doing it with one of my o lineman we built up to 20 trips with a 1 min rest

ass kicker

4

looks fun