Synchronizing Gait with Cardiac Cycle Phase Alters Heart Rate Response during Running.

Area of Science:

• Exercise Physiology
• Cardiovascular Dynamics
• Biomechanics

Background:

• Optimizing running economy is crucial for endurance performance.
• The cardiac cycle's phases (systole and diastole) influence cardiovascular load and perfusion.
• Timing biomechanical events with cardiac phases may offer physiological benefits.

Purpose of the Study:

• To investigate the heart rate (HR) and metabolic responses to running when foot strikes are synchronized with either the systolic or diastolic phase of the cardiac cycle.
• To determine if specific foot strike timing relative to cardiac events impacts physiological strain during running.

Main Methods:

• Ten elite male runners participated in a controlled treadmill running study at a constant speed (4.72 m/s).
• Participants used auditory cues to synchronize their foot strikes with either the ECG R-wave (systolic) or 45% into the R-R interval (diastolic).
• Continuous measurement of metabolic variables, heart rate, and ventilation was performed.

Main Results:

• Diastolic stepping resulted in significantly lower heart rate (HR) compared to systolic stepping (P < 0.001).
• Minute ventilation was significantly reduced during diastolic stepping versus systolic stepping (P < 0.001).
• Oxygen pulse (O2 pulse) was significantly higher during diastolic stepping, indicating enhanced stroke volume or oxygen extraction.

Conclusions:

• Synchronizing foot strikes with the diastolic phase of the cardiac cycle leads to reduced cardiovascular and ventilatory strain.
• This diastolic foot strike strategy may enhance physiological efficiency and potentially benefit distance running performance.
• Further research could explore the long-term effects and practical applications of cardiac-phase-timed running.