Adverse Events during a 12-Month Multisite Dose-Response Aerobic Exercise Intervention

Area of Science:

• Gerontology
• Exercise Physiology
• Public Health

Background:

• Older adults are encouraged to engage in regular physical activity.
• Understanding the safety profile of different exercise intensities is crucial for this demographic.

Purpose of the Study:

• To assess adverse event (AE) incidence in older adults during a year-long exercise intervention.
• To investigate dose-response relationships between exercise duration and AE frequency.
• To identify demographic factors associated with AE risk.

Main Methods:

• 648 older adults were randomized into stretching/toning (S&T), 150 minutes/week aerobic (150Ex), or 225 minutes/week aerobic (225Ex) groups.
• Adverse events were tracked, and rates were calculated based on adherence and time in study.
• Generalized linear models and post hoc comparisons analyzed AE incidence and incidence rate ratios (IRRs).

Main Results:

• 306 AE reported; 44% were intervention-related.
• No significant dose-response for all-cause AE.
• Intervention-related AE were higher in aerobic groups (150Ex: +77%, 225Ex: +88% vs. S&T).
• Higher adherence linked to fewer all-cause AE; comorbidity linked to more AE.

Conclusions:

• Aerobic exercise may elevate intervention-related AE risk but not all-cause AE risk across intensities.
• Higher exercise adherence is associated with fewer adverse events.
• Aerobic exercise is generally safe for older adults, with benefits likely exceeding risks.