Heart rate variability in exercising humans: Effect of water immersion

Renza Perini, Stefania Milesi, Luca Biancardi, David R. Pendergast, Arsenio Veicsteinas

Research output: Contribution to journalArticlepeer-review


Power spectrum analysis of heart-rate variability was made in seven men [mean age 22 (SEM 1) years] in head-out water immersion (W) and in air (A, control) at rest and during steady-state cycling to maximal intensity (maximum oxygen uptake, V̇O(2max)). At rest W resulted in a trebled increase in the total power (P <0.05), coupled with minimal changes in the power (as a percentage of the total) of the high frequency peak (HF, centred at 0.26 Hz; 18% vs 28%) and of the low frequency peak (LF, 0.1 Hz; 24% vs 32%). A third peak at about 0.03 Hz (very low frequency, VLF) represented the remaining power both in W and A. These changes as a whole indicated that immersion caused a vagal dominance in cardiac autonomic interaction, due to the central pooling of blood and/or the pressure of water on the trunk. Exercise caused a decrease in the total power in W and A. The LF% did not change up to about 50% V̇O(2max), thereafter decreasing towards nil in both conditions. The HF% decreased in similar ways in W and A to about half at 55%-60% V̇O(2max) and then increased to reach 1.5 times the resting values at V̇O(2max). The central frequency of HF increased linearly with oxygen uptake, showing a tendency to be higher in W than in A at medium to high intensities. The VLF% remained unchanged. The lack of differences in the LF peak between W and A during exercise would suggest that blood distribution had no effect on the readjustments in control mechanisms of arterial pressure. On the other hand, the findings of similar HF powers and the very similar values for ventilation in W and A confirmed the direct effect of the respiratory activity in heart rate modulation during exercise.

Original languageEnglish
Pages (from-to)326-332
Number of pages7
JournalEuropean Journal of Applied Physiology and Occupational Physiology
Issue number4
Publication statusPublished - Mar 1998


  • Arterial pressure control system
  • Cardiac autonomic system
  • Exertion
  • Heart rate variability
  • Water immersion

ASJC Scopus subject areas

  • Physiology
  • Public Health, Environmental and Occupational Health
  • Orthopedics and Sports Medicine
  • Physiology (medical)


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