TestingGuessing is less useful than checking the right athleteIf fatigue, low mood, illness, or bone stress keep showing up, testing is more useful than speculation.Coaches should notice patterns and refer, not prescribe protocols off instinct. Use the referral chain inside a school for who to tell, and in what order.
What not to doDo not use vitamin D as a catch-all explanationLow energy intake, low iron, poor sleep, and high load often travel with the same symptoms.Vitamin D matters, but it is rarely the only moving part.