Heart rate variability and critical flicker fusion frequency changes during and after parachute jumping in experienced skydivers
- 345 Downloads
The purpose of this study was (1) to further explore the heart rate dynamics and assess a potential cardiovascular risk in response to 4000 m jumps in experienced skydivers; (2) to assess whether there is an impact of such jumps on skydivers’ cortical arousal or not, which may impact their decision making processes.
18 experienced skydivers performed successive jumps from a plane at 4000 m of height. Heart rate dynamics and cortical arousal were assessed by the use of heart rate variability and Critical Flicker Fusion Frequency (CFFF), respectively.
CFFF did not differ between the three measurement time points (p > 0.05). Mean heart rate increased during the jump (p < 0.001) and came back to pre-jump values after the jump (p < 0.001). Percentage of the differences of successive NN intervals greater than 50 ms (pNN50) decreased during the jump (p < 0.001) and kept lower values after the jump compared to pre-jump (p < 0.05). High-frequency power (HF) did not differ during the jump (p > 0.05) but decreased after the jump compared to both pre-jump (p < 0.01) and jump (p < 0.05). Sample entropy decreased during the jump (p < 0.001) and came back to pre-jump values after the jump (p > 0.05).
These results confirm a vagal input reduction associated with a rise of the sympathetic tone during the jump and suggests that the experienced skydiver is not exposed to a high cardiovascular risk. This study also shows that environmental stresses induced by free fall could not hamper the perceptual vigilance of experienced skydivers.
KeywordsHuman Free fall Non-linear analysis Fractal Adverse effects Environmental stress Autonomic nervous system Physiology
Analysis of variance
Autonomic nervous system
Critical flicker fusion frequency
Heart rate variability
Percentage of the differences of successive NN intervals greater than 50 ms
Square root of the mean squared differences between successive RR intervals
Respiratory sinusal arythmia
Standard deviation of the points perpendicular to the line-of-identity of the Poincaré plot
Standard deviation along the line-of-identity of the Poincaré plot
The authors would like to thank the Ecole Française de parachute Midi Pyrénées “Bouloc Skydive” and all the subjects who participated in this study, as well as Nicolas Marrone for kindly designing Fig. 1. The authors would also like to acknowledge the PHYPODE project, financed by the European Commission under the FP7-PEOPLE-2010-ITN program (Grant Agreement No. 264816).
Conflict of interest
- Acharya U, Kannathal N, Sing O, Ping L, Chua T (2004) Heart rate analysis in normal subject of various age groups. Biomed Eng Online 3(1):24Google Scholar
- Acharya UR, Paul Joseph K, Kannathal N, Lim CM, Suri JS (2006) Heart rate variability: a review. Med Biol Eng Comput 44(12):1031–1051Google Scholar
- Allison AP, Peres JC, Boettger C, Leonbacher U, Shitcliff A, Elizabeth A (2012) Fight, flight, or fall: autonomic nervous system reactivity during skydiving. Personal Individ Diff 53:218–223Google Scholar
- Analitis A, Katsouyanni K, Biggeri A, Baccini M, Forsberg B, Bisanti L, Kirchmayer U, Ballester F, Cadum E, Goodman PG, Hojs A, Sunyer J, Tiittanen P, Michelozzi P (2008) Effects of cold weather on mortality: results from 15 European cities within the PHEWE project. Am J Epidemiol 168(12):1397–1408. doi: 10.1093/aje/kwn266 PubMedGoogle Scholar
- Davranche KP, Pichon A (2005) Critical flicker frequency threshold increment after an exhausting exercise. J Sport Exerc Psychol 27:515–520Google Scholar
- Hemelryck W, Rozloznik M, Germonpre P, Balestra C, Lafere P (2013) Functional comparison between critical flicker fusion frequency and simple cognitive tests in subjects breathing air or oxygen in normobaria. Diving Hyperb Med J South Pacific Underw Med Soc 43(3):138–142Google Scholar
- Hindmarch I (1982) Critical flicker fusion frequency (CFF): the effects of psychotropic compounds. Pharmacopsychiatry 15:44–48Google Scholar
- Hultgren HN (1992) Effects of altitude upon cardiovascular diseases. J Wilderness Med 3(3):301–308Google Scholar
- Hunter KM, Zacharias M, Parkinson R, Luyk NH (1994) Effect of flumazenil on the recovery from intravenous midazolam. N Z Dental J 90(399):9–12Google Scholar
- Krstacic G, Krstacic A, Smalcelj A, Milicic D, Jembrek-Gostovic M (2007) The “Chaos Theory” and nonlinear dynamics in heart rate variability analysis: does it work in short-time series in patients with coronary heart disease? Ann Noninvasive Electrocardiol 12(2):130–136. doi: 10.1111/j.1542-474X.2007.00151.x PubMedGoogle Scholar
- Leach JG, Griffith R (2008) Restrictions in working memory capacity during parachuting: a possible cause of ‘no pull’ failures. Appl Cogn Psychol 57:147–157Google Scholar
- Liu XX, Lu LL, Zhong CF, Cheng ZH, Yuan Q, Ren HR (2001) Analysis of heart rate variability during acute exposure to hypoxia. Space Med Med Eng 14(5):328–331Google Scholar
- Porta A, D’Addio G, Guzzetti S, Lucini D, Pagani M (2004) Testing the presence of non stationarities in short heart rate variability series. Comput Cardiol 31:645–648Google Scholar
- Schillaci C, Fazio O (1967) Critical fusion frequency. Its changes after ingestion of alcohol. Bollettino d’oculistica 46(10):772–782Google Scholar
- Struzik ZR, Hayano J, Sakata S, Kwak S, Yamamoto Y (2004) 1/f scaling in heart rate requires antagonistic autonomic control. Phys Rev E 70(5 Pt 1):050901Google Scholar
- Task Force (1996) Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation 93(5):1043–1065Google Scholar
- Taverniers J, Smeets T, Lo Bue S, Syroit J, Van Ruysseveldt J, Pattyn N, von Grumbkow J (2011) Visuo-spatial path learning, stress, and cortisol secretion following military cadets’ first parachute jump: the effect of increasing task complexity. Cogn Affect Behav Neurosci 11(3):332–343. doi: 10.3758/s13415-011-0043-0 PubMedGoogle Scholar
- Vigo DE, Lloret SP, Videla AJ, Chada D, Hunichen H, Mercuri J, Romero R, Siri L, Cardinali D (2010) Heart rate nonlinear dynamics during sudden hypoxia at 8230 m simulated altitude. Wilderness Environ Med 20:4–10Google Scholar