Background Catecholamine and cortisol are markers of hormonal stress in young female athletes and may indicate adaptation to an active lifestyle and sports activity.

Objective To discover if volleyball training produces changes in catecholamine and cortisol.

Design We performed a prospective study during a sports season (September–May) with monthly measurements of catecholamine and cortisol in urine collected over a 24-h period, on a rest day and between days 5 and 25 of the menstrual cycle.

Setting and participants 24 women (mean age 17±0.5 years; height: 172.8±4.7 cm; weight: 60.7±3.8 kg), volleyball players from two youth teams competing regionally (years of training: 3±0.4) and 24 sedentary women (ages: 17±0.9; height: 161±5.8 cm; weight: 58±5.6) selected from the high school. Participating teams: Ranked first and second last season. All players who started the study completed it. None of the participants were taking contraceptives or receiving hormonal treatments.

Interventions The players trained four days/week (an average of 8.3 h/week) and played 24 official matches. The sedentary women attended a physical education class 2 days/week (2 h/week), along with the players. Independent Variables: exercise, volleyball training and healthy lifestyle. Dependent Variables: urinary catecholamines and cortisol.

Results The sedentary participants had higher levels of epinephrine, norepinephrine, dopamine, metanephrine, normetanephrine and cortisol than the women athletes (p<0.05). Higher levels of catecholamines were recorded in September and October in both groups, whereas cortisol levels were higher in April and May. All levels were in normal ranges. There were no significant differences between players based on minutes of competition.

Conclusions Playing volleyball and following a healthy lifestyle do not increase levels of catecholamines and cortisol in well-trained adolescent girls.