This one is hard to classify, but it sure is fun and pumpy. Set up as if you're doing a wall-sit, but with a partner. Get comfortable in the back-to-back position, then extend your arms. Now "stick" your forearms and wrists together; whatever your partner does, stay connected. Begin the physical negotiation: one person may be more of a coach and leader, but this relationship can switch at any time. Listen with your body. sticky-back-arms

The goal is to produce big, smooth, pumpy moves in all planes. The most obvious movements are in the frontal plane, transverse plane and combinations such as figure eights. And of course, the whole time you're getting it dialed in, your quads will be doing their thing! Bonus: you'll also get an upper back massage with this one. For more about partner-resist and other innovative training games, see