Intra-Individual Variation of HRV during Orthostatic Challenge in Elite Male Field Hockey Players

Area of Science:

• Sports Science
• Physiology
• Autonomic Nervous System Research

Background:

• Understanding intra-individual variation in physiological markers is crucial for monitoring elite athletes.
• Orthostatic challenges provide insights into autonomic nervous system (ANS) function.
• Heart rate variability (HRV) and heart rate are key indicators of ANS status.

Purpose of the Study:

• To examine the intra-individual variation of HRV and heart rate in elite male athletes during an orthostatic challenge.
• To assess the reliability of HRV and heart rate measurements in supine and standing positions.
• To provide data for identifying true individual changes in ANS indices.

Main Methods:

• Log-transformed HRV metrics and heart rate were measured in elite male athletes upon waking.
• Measurements included supine (0-3 min and 3-6 min) and standing positions using the Rusko protocol.
• RM-ANOVA, ICC, and SEmeas were used to analyze intra-individual variation and reliability.

Main Results:

• Time and frequency domain HRV metrics exhibited low variation (CV% <8.5%; SEmeas% ≤4.0%) in the initial 0-3 min supine segment.
• No significant improvement in HRV variation was observed during the 3-6 min supine period.
• Standing HRV showed lower reliability (ICC) and higher measurement error (SEmeas) compared to supine values.
• Heart rate variability and reliability outcomes were comparable to log-transformed HRV metrics.

Conclusions:

• Elite male athletes demonstrate low intra-individual variation in HRV and heart rate during an orthostatic challenge.
• Supine HRV measurements (0-3 min) offer reliable data for monitoring ANS function.
• These findings aid in distinguishing genuine physiological adaptations from measurement variability in athletes.