Interval training in elderly men increases both heart rate variability and baroreflex activity

Clin Auton Res. 2005 Apr;15(2):107-15. doi: 10.1007/s10286-005-0251-1.

Abstract

Aims: Autonomic nervous system activity decreases continuously with age and appears to be a powerful predictor of disease and death. Attempts are thus made to reactivate autonomic drive with the intent of improving health.

Methods: We assessed maximal oxygen consumption (VO2max), autonomic nervous system activity by heart rate variability (HRV) analysis and spontaneous cardiac baroreflex activity (SBR) in eleven elderly men (73.5+/-4.2 years) before and after a 14-week program of intensive cycloergometer interval training. The standard HRV indices were calculated using time domain (mean RR, PNN50, RMSSD, SDNN, SDANN and SDNNIDX), and Fourier transform (total power, ULF,VLF, LF, LFnu, HF, HFnu and LF/HF) analyses of 24-hour, daytime and nighttime Holter recordings. The SBR was calculated from 15-minute recordings of spontaneous blood pressure and RR interval variations using the sequence (slope, slSBR) and cross-spectral (alphaSBRHF and alphaSBRLF) methods.

Results: After the training period,VO2max increased by 18.6 % (26.8+/-4.4 to 31.8+/-5.2 ml.kg(-1).min(-1), p<0.01). The nocturnal parasympathetic indices of HRV increased (PNN50: 3.05+/-2.21 to 5.00+/-2.87%, RMSSD: 29.1+/-7.6 to 38.8+/-10.9 ms, HF: 117+/-54 to 194+/-116 ms2/Hz, all p<0.05) as did the SBR indices (slSBR: 7.0+/-1.8 to 9.8+/-2.1 ms.mmHg(-1), p<0.01; alphaSBRHF: 6.9+/-2.2 to 10.5+/-3.7 ms.mmHg(-1), p<0.05; alphaSBRLF: 5.3+/-2.3 to 6.9+/-3.1 ms.mmHg(-1), p=0.22).

Conclusion: Intensive endurance training in elderly men enhanced parasympathetic parameters of HRV and, interestingly, of SBR. Physiological mechanisms and long-term clinical effects on health status should be further investigated.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged / physiology*
  • Anaerobic Threshold / physiology
  • Baroreflex / physiology*
  • Electrocardiography, Ambulatory
  • Exercise Test
  • Fourier Analysis
  • Heart Rate / physiology*
  • Humans
  • Male
  • Oxygen Consumption / physiology
  • Parasympathetic Nervous System / physiology
  • Physical Fitness / physiology*