Stand tall with your fingers resting lightly by your ears, elbows out wide. Lift one knee up in front of you and crunch down and across, bringing your opposite elbow toward it - your torso rotating and folding slightly as knee and elbow close the gap. Return to standing tall and repeat on the other side, alternating in a steady rhythm. It's the crunch that counts: squeeze through your midsection at the touch instead of just tapping and moving on.

Works: abs, obliques, hip flexors

Breathing: Exhale as knee and elbow come together, inhale as you return to standing.

Common Mistakes: Bowing forward from the waist without any rotation, pulling the elbow down while the knee barely rises, and rushing through taps without the squeeze.

Make Easier: Lift the knee only as high as comfortable and let the elbow travel further to meet it, slowing the whole movement down.

Make Harder: Pause and squeeze for a beat at every touch, pick up the pace, or take it to the floor with Knee-to-Elbow (Floor) or up-tempo with High Knees.