The fourth workout of this seasons CrossFit Open has been announced, and our first piece of advice for 20.4 is this: start and . You'll be doing box jumps, single-leg squats, and clean and jerks.

Stand with your feet slightly wider than hips-width distance apart in front of a sturdy plyometrics box that's six to 24 (or more!) inches tall. Bend your knees and swing your arms back. Jump onto the ...