Photo credits: Top, courtesy of Whoop; Step 1, James Michelfelder; Step 2, Getty Images/technotr.
1. Start in a pushup position with elbows extended.
2. From that position, sprint forward 10 yards, driving feet hard into the ground. Make sure to drive your feet and arms back and down in a piston-like motion. After 10 yards, slow down and stop. That's one rep.