The 24-h urinary cortisol/cortisone ratio for monitoring training in elite swimmers.

Purpose: The effect of training variations on 24-h urinary cortisol/cortisone (C/Cn) ratio was investigated in highly trained swimmers to determine whether it could be a good marker of training stress and performance.

Methods: Fourteen swimmers (five female and nine male) were tested after 4 wk of intense training (IT), 3 wk of reduced training (RT), and 5 wk of moderate training (MT). At the end of each period, the swimmers performed in their best event at an official competition.