Time-frequency analysis of heart rate variability during immediate recovery from low and high intensity exercise
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Previous studies have neglected the first recovery minutes after exercise when studying post-exercise heart rate variability (HRV). The present aim was to evaluate autonomic HR control immediately after exercise using Short-time Fourier transform (STFT) and to compare the effects of low [LI, 29(6)% of maximal power] and high [HI, 61(6)% of maximal power] intensity bicycle exercise on the HRV recovery dynamics. Minute-by-minute values for low (LFPln, 0.04–0.15 Hz) and high (HFPln, 0.15–1.0 Hz) frequency power were computed from R-R interval data recorded from 26 healthy subjects during 10 min recovery period after LI and HI. The HRV at the end of exercise and recovery was assessed with Fast Fourier transform as well. The results showed that LFPln and HFPln during the recovery period were affected by exercise intensity, recovery time and their interaction (P < 0.001). HFPln increased during the first recovery minute after LI and through the second recovery minute after HI (P < 0.001). HFPln was higher for LI than HI at the end of the recovery period [6.35 (1.11) vs. 5.12 (1.01) ln (ms2), P < 0.001]. LFPln showed parallel results with HFPln during the recovery period. In conclusion, the present results obtained by the STFT method, suggested that fast vagal reactivation occurs after the end of exercise and restoration of autonomic HR control is slower after exercise with greater metabolic demand.
KeywordsAutonomic nervous system Short-time Fourier transform Heart rate variability
This study was funded by grants from the Ministry of Education, Finland, and from TEKES-National Technology Agency of Finland. The authors thank Ph.D. Sami Saalasti for his help in performing the heart rate variability analyses. This study was partly funded by a grant from Sunto Ltd, Finland and Firstbeat Technologies Ltd, Finland. Heikki Rusko is currently stockowner of Firstbeat Technologies Ltd, Finland.
- Akselrod S, Gordon D, Madwed JB, Snidman NC, Shannon DC, Cohen RJ (1985) Hemodynamic regulation: investigation by spectral analysis. Am J Physiol Heart Circ Physiol 249:H867–H875Google Scholar
- Arai Y, Saul JP, Albrecht P, Hartley LH, Lilly LS, Cohen RJ, Colucci WS (1989) Modulation of cardiac autonomic activity during and immediately after exercise. Am J Physiol Heart Circ Physiol 256: H132–H141Google Scholar
- Kaikkonen P, Nummela A, Rusko H (2007a) Heart rate variability dynamics during early recovery after different endurance exercises. Eur J Appl Physiol (accepted for publication)Google Scholar
- Kaikkonen P, Rusko H, Martinmäki K (2007b) Post-exercise heart rate variability of endurance athletes after different high-intensity exercises. Scand J Med Sci Sports (accepted for publication)Google Scholar
- Oppenheim A, Schafer RW (1999) Discrete-time signal processing. Prentice Hall, Upper Saddle RiverGoogle Scholar
- Pagani M, Lombardi F, Guzzetti S, Rimoldi O, Furlan R, Pizzinelli P, Sandrone G, Malfatto G, Dell’Orto S, Piccaluga E, Turiel M, Baselli G, Gerutti S, Malliani A (1986) Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympathovagal interaction in man and conscious dogs. Circ Res 59:178–193PubMedGoogle Scholar
- Rowell LB (1986) Human circulation regulation during physical stress. Oxford University Press, New York, pp. 213–256Google Scholar
- Task Force of the European Society of Cardiology, the North American Society of Pacing and Electrophysiology (1996) Heart rate variability. Standard of measurement, physiological interpretation and clinical use. Circulation 93:1046–1065Google Scholar