Endocannabinoids and heart rate variability alterations after exposure to prolonged intensive physical exercise of the Hellenic Navy SEALs

Abstract Background Recent research indicates that endocanabinoids (eCB) and heart rate variability (HRV) are associated with stress-induced experiences. However, these underlying mechanisms have not been elucidated. Purpose The aim of the present study is to investigate if exposure acute chronic stress promotes measurable changes concurrently peripheral eCB ligands HRV. Methods 13 candidates under intense preparation for their enlistment in Hellenic Navy SEALs (H.N.S.) participated study. All subjects underwent mental state examination, while HRV variables time frequency domains recordings were acquired. Furthermore, at baseline 30 days after prolonged intensive physical exercise hair collected order measure ligands, such as anandamide (AEA), 2-arachidonoylglycerol (2-AG), N-acyl ethanolamine (NAE) molecules: palmitoylethanolamide (PEA) oleoylethanolamide (OEA). Results Comparing basal concentrations before exercise, we found AEA, PEA OEA notably increased (p<0.01, p<0.05 p<0.01 respectively) whereas no differences observed regarding ligand 2-AG. Regarding domain features HRV, a strong positive correlation was between mean HR, AEA [r(13)=0.934, p<0.05, (r(13)=0.902, p<0.05]. domain, negative low (LF) (r(13)=−0.853, p<0.01). No statistically significant associations noted high EC ligands. Conclusions These findings suggest endocannabinoid-HRV interrelations might share short-term, long-term adaptability self-regulation stress. Further studies required determine validity signaling biomarker different aspects response. Funding Acknowledgement Type funding sources: Public grant(s) – National budget only. Main source(s): Region Attica