Cardiac work remains high after strength exercise in elderly

Area of Science:

• Exercise Physiology
• Cardiovascular Health
• Gerontology

Background:

• Moderate- to high-intensity strength training is recommended for healthy adults.
• Younger adults exhibit decreased blood pressure and elevated heart rate post-strength training.
• Cardiovascular responses to strength training in the elderly are not well-established.

Purpose of the Study:

• To investigate the acute effects of a single strength training session on hemodynamic variables and heart rate variability in elderly subjects.
• To compare these effects with those observed in younger populations.
• To determine the duration of these cardiovascular changes.

Main Methods:

• 16 elderly subjects participated in a randomized crossover study with Control and Exercise sessions.
• Exercise involved 3 sets of 8 repetitions at 85% of one-repetition maximum (8 RM) for 9 exercises.
• Hemodynamic variables and heart rate variability were measured pre- and post-intervention.

Main Results:

• Systolic blood pressure did not change post-exercise but increased post-control. Diastolic blood pressure and systemic vascular resistance increased similarly after both sessions.
• Cardiac output and stroke volume decreased post-exercise. Heart rate, rate-pressure product, and low- to high-frequency ratio of heart rate variability increased post-exercise.
• Ambulatory blood pressure remained similar, but heart rate and rate-pressure product were elevated for up to 4.5 hours post-exercise.

Conclusions:

• A single strength training session elevates cardiac sympathetic modulation and heart rate in elderly subjects.
• These effects lead to prolonged elevation of cardiac work in older adults.
• Elderly individuals exhibit distinct cardiovascular adaptations to strength training compared to younger adults.