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Exercise training improves left ventricular contractile response to beta-adrenergic agonist.
R J Spina1, T Ogawa, A R Coggan
1Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|January 1, 1992
Summary
Endurance exercise training enhances left ventricular function during beta-adrenergic stimulation in healthy adults. This improved cardiac response is key for better cardiovascular health.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Sedentary individuals may have suboptimal cardiac responses.
- Understanding exercise effects on cardiac function is crucial for public health.
Purpose of the Study:
- To investigate if endurance exercise training improves left ventricular function under beta-adrenergic stimulation.
- To assess changes in cardiac mechanics after a 12-week training program.
Main Methods:
- 16 healthy sedentary subjects (10 women, 6 men) underwent 12 weeks of endurance training.
- Left ventricular function assessed via echocardiography, both at rest and during isoproterenol infusion.
- Evaluated fractional shortening and end-systolic wall stress before and after training.
Main Results:
- Maximal oxygen uptake significantly increased post-training (41.0 to 49.3 ml.kg-1.min-1).
- Fractional shortening during isoproterenol infusion increased significantly after training (52% to 56%).
- The increase in fractional shortening at comparable end-systolic wall stress was significantly greater post-training.
Conclusions:
- Endurance exercise training enhances left ventricular contractile responsiveness to beta-adrenergic stimulation.
- Improved cardiac function suggests beneficial adaptations to exercise training.
- These findings highlight the positive impact of exercise on cardiovascular health.