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European Journal of Applied Physiology

, Volume 115, Issue 7, pp 1533–1545 | Cite as

Heart rate variability and critical flicker fusion frequency changes during and after parachute jumping in experienced skydivers

  • M. CavaladeEmail author
  • V. Papadopoulou
  • S. Theunissen
  • C. Balestra
Original Article

Abstract

Purpose

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.

Method

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.

Results

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).

Conclusion

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.

Keywords

Human Free fall Non-linear analysis Fractal Adverse effects Environmental stress Autonomic nervous system Physiology 

Abbreviations

ANOVA

Analysis of variance

ANS

Autonomic nervous system

CFFF

Critical flicker fusion frequency

ECG

Electrocardiogram

EEG

Electroencephalogram

FrD

Fractal dimension

HPA

Hypothalamic–pituitary–adrenal

LED

Light-emitting diode

LF

Low-frequency power

HF

High-frequency power

HR

Heart rate

HRV

Heart rate variability

pNN50

Percentage of the differences of successive NN intervals greater than 50 ms

RMSSD

Square root of the mean squared differences between successive RR intervals

RSA

Respiratory sinusal arythmia

SampEn

Sample entropy

SD1

Standard deviation of the points perpendicular to the line-of-identity of the Poincaré plot

SD2

Standard deviation along the line-of-identity of the Poincaré plot

Notes

Acknowledgments

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

None.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • M. Cavalade
    • 1
    Email author
  • V. Papadopoulou
    • 1
    • 2
  • S. Theunissen
    • 1
  • C. Balestra
    • 1
    • 3
  1. 1.Environmental, Occupational, Ageing and Integrative Physiology LaboratoryHaute Ecole Paul-Henri SpaakBrusselsBelgium
  2. 2.Department of BioengineeringImperial College LondonLondonUK
  3. 3.DAN Europe Research DivisionBrusselsBelgium

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