Plank High-Fives

No equipment, no learning curve and a built-in reason to smile. Face each other in high planks with about two feet between your hands, then both lift your right hands to slap, set them down, and do the same with your left, back and forth. It is harder than it sounds, because each high-five briefly leaves you on three points of contact. A partner who is newer to planks can hold the position from the knees while the other stays on the toes, and you still meet in the middle. Count high-fives instead of seconds and set a total you reach together.