Abstract
Previous studies on HR recovery (HRR) measures have utilized the supine and the seated
postures. However, the most common recovery mode in sport and clinical settings after
running exercise is active walking. The aim of the current study was to examine the
reliability of HR measures during walking (4 km · h−1) before and following a maximal test. Twelve endurance athletes performed an incremental
running test on 2 days separated by 48 h. Absolute (coefficient of variation, CV,
%) and relative [Intraclass correlation coefficient, (ICC)] reliability of time domain
and non-linear measures of HR variability (HRV) from 3 min recordings, and HRR parameters
over 5 min were assessed. Moderate to very high reliability was identified for most
HRV indices with short-term components of time domain and non-linear HRV measures
demonstrating the greatest reliability before (CV: 12–22%; ICC: 0.73–0.92) and after
exercise (CV: 14–32%; ICC: 0.78–0.91). Most HRR indices and parameters of HRR kinetics
demonstrated high to very high reliability with HR values at a given point and the
asymptotic value of HR being the most reliable (CV: 2.5–10.6%; ICC: 0.81–0.97). These
findings demonstrate these measures as reliable tools for the assessment of autonomic
control of HR during walking before and after maximal efforts.
Key words
autonomic nervous system - parasympathetic reactivation - sympathetic withdrawal
- heart rate complexity - detrended fluctuation analysis
