Heart rate variability before and after cycle exercise in relation to different body positions

Area of Science:

• Physiology
• Exercise Science
• Cardiovascular Regulation

Background:

• Autonomic nervous system (ANS) regulation is crucial for post-exercise recovery.
• Heart Rate Variability (HRV) is a non-invasive indicator of ANS activity.
• Body posture can influence cardiovascular regulation at rest.

Purpose of the Study:

• To investigate the impact of three body positions on HRV recovery after submaximal exercise.
• To determine if specific postures enhance the return of HRV to pre-exercise levels.

Main Methods:

• Thirty healthy males underwent 5-minute submaximal cycling exercise.
• HRV was measured at baseline and during 15-minute recovery in seated, supine, and supine-elevated leg positions.
• Time-domain (RRNN, SDNN, RMSSD) and frequency-domain (LF, HF) HRV parameters were analyzed.

Main Results:

• Post-exercise, supine positions showed significantly higher RRNN and RMSSD compared to seated.
• Elevated legs in supine position led to lower post-exercise LF compared to seated.
• Most HRV measures (time and frequency domain) remained below baseline levels 15 minutes post-exercise, irrespective of body position.

Conclusions:

• Fifteen minutes of recovery is insufficient for most HRV measures to return to pre-exercise levels after short-term exercise.
• Autonomic cardiac regulation modifications due to body posture persist post-exercise.
• The rate of cardiac autonomic recovery is influenced by body posture, though post-exercise differences varied from resting patterns.