Given the dramatic rise in sports participation, is there any recommendation on how to detect how much is too much?

Too much participation can certainly manifest with overuse injuries but it’s also important to pay attention for other signs your child is experiencing burnout. Look for fatigue, mood changes, sleeplessness, decline in academic performance, headaches, and signs of stress. Overuse injuries typically occur slowly over time, these injuries tend to cause discomfort after the athletes trains.  It is important to listen for these complaints.  I do not advise playing through this type of pain. There are many resources available for baseball players in regards to how many pitches can be thrown at any given age (www.stopsportsinjuries.com).  In general, for most sports I advise the athlete have a true offseason to allow their body to rest and recover.  Mixing athletic endeavors may actually improve overall conditioning and coordination.