This move not only improves your flexibility, but also your balance. Variations include putting your back knee on the ground rather than having it lifted. "How-to: Start on your hands and knees. Step your right foot between your hands into a lunge, keeping your right knee directly above your heel. Inhale and slowly lift your back knee off the floor. Press your back heel toward the wall behind you as you begin to straighten your back leg. Inhale and lift your arms overhead. Keep your spine long as you hold for 1 minute and breathe. Switch sides, doing each side twice. Why it's good for you: Tight hips can cause lower back pain, knee strain, and injury, which can keep you out of the game, out of the gym, and suffering at your desk. Adding crescent lunge to your pre-workout routine can help you open your hips."