Aim: 

The alpine potholing is as an extreme sport with its unique environmental characteristics and heavy effort, practiced in Karst caves characterized by great depth, cold and high humidity. Scuba diving is associated with environmental factors that may affect cardiovascular functions and cause psychological stress. This study aims at clarifying the endocrine expression of exercise and psychological stress in a potholer before and after diving in an alpine cave siphon, using prolactin (PRL), testosterone (T) and cortisol levels as exercise-stress markers.

Methods: 

One élite male potholer as well as cave-diver was tested before and after the immersion (imm) in a siphon at bottom of a cave 700 m deep. The potholer repeated imm in 2 different days following the same schedule. Blood samples were withdrawn: (1) at pre-siphon imm at the bottom of the cave, (2) at post-siphon imm (after about 45 minutes), (3) in hospital 24 hours after the siphon imm. Serum PRL, T and cortisol were analyzed with a chemiluminescence assay.

Results: 

After imm PRL (ng/ml) was 32% higher (pre-imm: 3.7 - post-imm: 4.9), cortisol (ng/ml) increased 19% (pre-imm: 190.3 – post-imm: 225.8), whereas T (ng/ml) decreased 40% (pre-imm: 1.5 - post-imm: 0.9). The day after the cave-siphon diving the PRL and cortisol presented the lowest value (PRL: 3.0 ng/ml; cortisol: 140.0 ng/ml), whereas the T value corresponded to 3.8 ng/ml.

Conclusion: 

Our data confirm that extreme physiological/psychological conditions of cave diving are stressors able to alter the hormonal response in an élite potholer. The marked increase of PRL values after diving underlines the great intensity of cave diving effort, while the increase of cortisol as well as the decrease of T are likely due to the combination of emotional stress and exercise.