Last year a new client came to me with a problem. She should have been in incredible shape -- she was running 50+ miles a week, doing yoga daily and training for her first triathlon. Despite her best efforts, however, she found her performance had plateaued or even decreased. Digging deeper, I asked about her mood and sleeping habits. "The smallest things annoy me," she said. Her sleep, diet and performance at work were all out of whack too. Her problem: overtraining.