Qigong - Fly Hands (a.k.a. Knocking on the Door of Life)
This exercise is a wonderful way to open up the joints of the spine. The feet are a little wider than hip distance apart. The knees are slightly bent. Stand in good alignment and then start to turn slowly to the right and then the left. Rotate at the hips and not just at your ribcage or shoulders. Your hips can turn about 45 degrees from center towards each side. Look over your shoulder as you turn and let your arms swing. As you gain momentum, the arms are going to slap along the low back and the waist. Get the feeling of the upper body being a rag doll. It is loose, and the arms are just going along for the ride. The hips and waist are active and driving all the movement.
You can also download a free metronome app, and set it for about 50-55 bpm. Set a timer for 3 minutes, and rotate your torso to one side with each beat of the metronome. A typical dragon boat race will last under 3 minutes, so you can practice getting in the number of torso rotations that you would in an actual race. You may feel quite invigorated after doing this for 3 minutes!