Analysis of heart rate variability in Chinese PLA navy global visiting task group

AIM:To analyze the heart rate variability in Chinese PLA navy global visiting task group. METHODS: We analyzed the heart rate variability from Holter recordings in 77 males and four females 5-15 days before voyage and 65-75 and 115-125 days on the voyage, and in 29 males and 3 females 5-15 days after voyage. RESULTS: NN50 and VLF were lower in the 77 males and four females 65-75 days on the voyage compared with those 5-15 days before voyage (P<001). SDANN was lower in the 77 males and four females 115-125 days on the voyage than at 65-75 days on the voyage (P<001). SDNN, SDANN, SDNN, RMSSD, NN50, PNN50, triangular index, VLF, HLF, VAI and VLI in the 77 males and four females 65-75 days on the voyage were lower than those 5-15 days before voyage (P<001). CONCLUSION: Long voyages may reduce heart rate variability.