Doctors explain why this common evening habit can lead to a late night second wind of energy, which can contribute to waking up at 3 a.m.

Waking up at 3 a.m. with a racing mind is exhausting. I put a top doctor's simple brain technique to the test to see if it could shut off my late-night anxiety.

Doctors explain why this common evening habit can lead to a late night second wind of energy, which can contribute to waking up at 3 a.m.