Okay just needed to be sure before giving you any real suggestions. Wouldn't want to tell you to do a stretch or strengthening exercise when it turns out it was fracture all along and made things worse. That would just be no good for anyone. When it comes to injuries, always, always, always, seek out a medical professional.
The fact that the pain comes and goes with activity is consistent with a repetitive stress/overuse injury such as tendinitis. Tendinitis is a swelling of connective tissue from repetitive or excessive movements. I'm no medical professional, but if I had to put money on it, I would be willing to bet that doctor probably said something similar to you at one point or another.
Short term ways to deal with discomfort include taking an anti-inflammatory pain medicine, such as Advil prior to practice, making sure you warm-up and stretch your wrists well before tumbling, and making sure you ice your wrists for 20 min after every practice.
Long term solutions include strengthening of the wrists so that they can handle larger loads for longer periods of time. The best exercises to do this would be weight baring exercises that do not have a heavy impact. An example of a good exercise would be bear crawls, push-ups, headstands, and handstands . A bad exercise would be back handsprings, due to the high impact created from blocking through the shoulders. You could also use exercise bands, and hand weights to perform other specific wrist strengthening exercises. Though, your best solution would be to see a physical therapist or athletic trainer who can design a specific exercise prescription to best suit your needs.
Best of luck! Hope you feel better.
Coach Matt
