The influence of external stressors on physiological testing: Implication for return-to-play protocols

Area of Science:

• Physiology
• Sports Science
• Autonomic Nervous System Research

Background:

• External stressors (alcohol, caffeine, exercise) affect cellular homeostasis and the autonomic nervous system (ANS).
• Limited data quantifies the impact of these stressors on physiological testing accuracy.
• Pre-season physiological baseline testing in sports is common but lacks standardized stressor guidelines.

Purpose of the Study:

• To assess the impact of alcohol, caffeine, and exercise on spontaneous baroreflex sensitivity (BRS), heart rate variability (HRV), heart rate asymmetry (HRA), and blood pressure variability (BPV).
• To determine if external stressors compromise the reliability of physiological measurements in athletes.
• To highlight the need for standardized protocols in sports-related physiological testing.

Main Methods:

• Seventeen male varsity athletes underwent two identical physiological assessments within a week, one with stressors and one without.
• Measurements included continuous beat-to-beat blood pressure and ECG during rest and a squat-stand maneuver.
• Calculated metrics: BRS, HRV, HRA, and systolic blood pressure variability (BPV).

Main Results:

• Significant decreases in HRV and HRA metrics, HRV total power, and BRS-up sequences were observed during assessments with stressors.
• High-frequency HRV decreased, while BRS-pooled increased when exercise was the sole stressor.
• These findings indicate that common external factors alter physiological test outcomes.

Conclusions:

• External stressors demonstrably impact key physiological metrics used in athlete assessments.
• Current pre-season testing protocols may yield unreliable data due to unaddressed stressors.
• Stringent, standardized guidelines are necessary for accurate and dependable baseline physiological testing in sports.