Changes in cortisol and testosterone levels and T/C ratio during an endurance competition and recovery

To describe the evolution of cortisol and testosterone levels and testosterone/cortisol (T/C) ratio in long-distance runners during a relay competition and during the three days following the competition.

Two teams of four relayers (one male, one female) took part into this six-hour relay race. Hormonal control during the race was made possible thanks to saliva sampling during rest periods at each relay. The runners were subelite runners, (VO2max = 67.0 ml x min(-1) x kg(-1) in males and 56.8 ml x min(-1) x kg(-1) in females).

During the race, cortisol levels reached approximately 1.5-fold basal levels. These levels remained high till late evening, (higher than morning values, when normal resting levels are 4 to 6-folds lower). Surprisingly, wakening levels during the following days were lower than resting levels. Testosterone did not vary in females; then, male values only are reported. During the race they decreased gradually and remained low till night. During the following three days, testosterone levels were higher than resting day levels. The T/C ratio amplifies these variations: low during the race till retiring, (currently associated with a catabolic tendency) and reversely high during the following three days (associated with a high anabolic tendency).

As expected, a catabolic tendency occurs during a long distance run (increase in cortisol level followed by a drop in testosterone level). More surprising is the high anabolic tendency noted during the recovery period (low cortisol and high testosterone levels).