PT  - JOURNAL ARTICLE
AU  - Klugar, Miloslav
AU  - Stejskal, Pavel
AU  - Krejčíř, Václav
AU  - Bartáková, Olga
AU  - Drbošalová, Veronika
AU  - Kozáková, Jitka
AU  - Štěpaník, Petr
TI  - Changes in autonomic nervous system activity in connection with scuba diving
DP  - 2009 Mar 1
TA  - Acta Universitatis Palackianae Olomucensis. Gymnica
PG  - 7--12
VI  - 39
IP  - 2
IS  - 23364912
AB  - Objective: The purpose of this study was to discover how the autonomous nervous system (ANS) responds to scuba diving with recreation parameters. 
Methods: The sample consisted of 20 scuba divers, 17 men and 3 women, who submitted to measurement in Sharm El Sheikh, Egypt. ANS activity was evaluated before diving (immersion) in water (depth of 20 meters) and 20 minutes after the  dive (the total time under water was 43.3 ± 2.2 minutes) by means of spectral analysis (SA) of heart rate variability (HRV). HRV was measured during a standardized orthoclinostatic manoeuvre (three times 300 beats or three times 5 minutes) by means of Varcor multi PF7 and Varcor PF6. The standard parameters and complex indexes of SA HRV were applied to assessments of ANS activity. 
Results: A significant increase in the total spectral power and parameters of vagal activity (MSSD and complex index of vagal activity) occurred 20 minutes after cessation of scuba diving. The spectral power shifted from slower to quicker fluctuations - the VLF/HF and LF/HF ratios nonsignificantly decreased and the complex index of sympathovagal  balance significantly increased. All of these changes suggest that 30 minutes after scuba diving there was significant increased vagal activity. 
Conclusions: Scuba diving at a depth of 20 meters led to an increase in vagal activity that persisted for 30 minutes after diving.