TY  - JOUR
A1  - Gronwald, Thomas
A1  - Hoos, Olaf
T1  - Correlation properties of heart rate variability during endurance exercise: A systematic review
T2  - Annals of Noninvasive Electrocardiology
N2  - Background
Non‐linear measures of heart rate variability (HRV) may provide new opportunities to monitor cardiac autonomic regulation during exercise. In healthy individuals, the HRV signal is mainly composed of quasi‐periodic oscillations, but it also possesses random fluctuations and so‐called fractal structures. One widely applied approach to investigate fractal correlation properties of heart rate (HR) time series is the detrended fluctuation analysis (DFA). DFA is a non‐linear method to quantify the fractal scale and the degree of correlation of a time series. Regarding the HRV analysis, it should be noted that the short‐term scaling exponent alpha1 of DFA has been used not only to assess cardiovascular risk but also to assess prognosis and predict mortality in clinical settings. It has also been proven to be useful for application in exercise settings including higher exercise intensities, non‐stationary data segments, and relatively short recording times.

Method
Therefore, the purpose of this systematic review was to analyze studies that investigated the effects of acute dynamic endurance exercise on DFA‐alpha1 as a proxy of correlation properties in the HR time series.

Results
The initial search identified 442 articles (351 in PubMed, 91 in Scopus), of which 11 met all inclusion criteria.

Conclusions
The included studies show that DFA‐alpha1 of HRV is suitable for distinguishing between different organismic demands during endurance exercise and may prove helpful to monitor responses to different exercise intensities, movement frequencies, and exercise durations. Additionally, non‐linear DFA of HRV is a suitable analytical approach, providing a differentiated and qualitative view of exercise physiology.
KW  - alpha1
KW  - autonomic nervous system
KW  - detrended fluctuation analysis
KW  - endurance exercise
KW  - heart rate variability
KW  - short‐term scaling exponent
Y1  - 2020
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/21354
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-213548
VL  - 25
IS  - 1
ER  -