Behavior of Heart Rate Variability After 10 Repetitions Maximum Load Test for Lower Limbs

Area of Science:

• Exercise Physiology
• Cardiovascular Health
• Autonomic Nervous System Function

Background:

• Heart rate variability (HRV) is a key indicator of autonomic nervous system balance.
• Understanding HRV responses to maximal exercise is crucial for safety and training prescription.
• Previous research has not fully elucidated HRV changes after 10 repetitions maximum (10RM) load tests.

Purpose of the Study:

• To analyze acute heart rate variability (HRV) changes following a 10 repetitions maximum (10RM) load test in normotensive women.
• To assess the impact of 10RM testing on sympathetic nervous system activity post-exercise.
• To determine the safety and applicability of 10RM testing for resistance training prescription.

Main Methods:

• Eight recreationally trained women underwent two 10RM testing sessions for leg exercises (back squat, leg press, leg extension, leg flexion) with 48-hour rest.
• Heart rate variability (HRV) was measured at baseline and 15, 30, 45, and 60 minutes post-exercise.
• Time and frequency domain HRV indices were analyzed to assess autonomic responses.

Main Results:

• Significant differences in RMSSDms, MRRms, MHR, and PNN50% were observed 15 minutes post-exercise compared to baseline.
• No significant differences in other HRV indices or comparisons beyond 15 minutes post-exercise were found.
• The 10RM load test did not lead to prolonged or excessive post-exercise sympathetic overactivity.

Conclusions:

• The 10 repetitions maximum (10RM) load test appears safe for cardiovascular healthy individuals, as it does not induce exacerbated postexercise sympathetic activity.
• These findings support the use of 10RM testing by exercise practitioners for accurate resistance training load prescription.
• The acute HRV response to 10RM testing indicates a manageable physiological stress for the studied population.