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Central hemodynamics during progressive upper- and lower-body exercise and recovery
Summary
This study compared cardiac responses to upper- and lower-body exercise. Immediately after moderate to high intensity exercise, cardiac output decreases due to reduced heart rate and stroke volume.
Area of Science:
- Exercise Physiology
- Cardiovascular Physiology
Background:
- Understanding the cardiovascular response to different exercise modalities is crucial for exercise prescription.
- Previous research has focused on lower-body exercise, with less known about upper-body exercise effects on stroke volume and contractility.
Purpose of the Study:
- To compare stroke volume (SV) and myocardial contractility during and after upper- and lower-body exercise.
- To investigate the impact of exercise intensity on cardiovascular recovery.
Main Methods:
- Nine healthy men performed incremental exercise tests on an arm crank and cycle ergometer.
- Impedance cardiography measured cardiac output (Q), SV, and contractility beat-by-beat.
- Measurements were taken during exercise and a 15-second recovery period.
Main Results:
- Cardiac output (Q) increased linearly with power output (PO), while total peripheral resistance decreased exponentially.
- During recovery, Q and heart rate (HR) decreased at all PO levels.
- Stroke volume (SV) significantly decreased during recovery after exercise VO2 exceeded 1.0 L/min for both exercise types.
Conclusions:
- Immediately after low-intensity exercise, cardiac output reduction is primarily due to decreased heart rate.
- Following moderate- to high-intensity exercise, reduced cardiac output results from decreases in both heart rate and stroke volume.