Left ventricular response in healthy young men during heavy-intensity weight-lifting exercise

Area of Science:

• Exercise Physiology
• Cardiovascular Physiology
• Sports Science

Background:

• Understanding the cardiovascular response to resistance exercise is crucial for athletes and clinicians.
• Previous research has indicated significant hemodynamic alterations during intense physical exertion.

Purpose of the Study:

• To investigate the dynamic changes in cardiac volumes, blood pressure, and intrathoracic pressure during maximal effort leg press exercise.
• To correlate these cardiovascular parameters with different phases of the weight-lifting movement.

Main Methods:

• Healthy males performed leg press exercise to failure at 95% of their maximum dynamic strength.
• Echocardiography was used to measure cardiac volumes (end-diastolic and end-systolic volumes).
• Intra-arterial blood pressure and intrathoracic pressure were continuously monitored.

Main Results:

• During the lifting phase, end-diastolic volume and end-systolic volume significantly decreased, while heart rate, systolic blood pressure, diastolic blood pressure, and intrathoracic pressure significantly increased.
• Stroke volume showed a decrease, though not statistically significant.
• Following full knee extension, most parameters returned to baseline, except for end-systolic volume, heart rate, and intrathoracic pressure.
• During the lowering phase, cardiac volumes decreased, and blood pressures increased.

Conclusions:

• Intense resistance exercise, such as the leg press, induces rapid and significant alterations in cardiac function and hemodynamics.
• These cardiovascular changes are phase-dependent, varying between the lifting and lowering phases of the exercise.
• The findings highlight the complex interplay between mechanical loading, cardiac output, and vascular resistance during weight lifting.