Fatigue and Physical Activity After Myocardial Infarction

BACKGROUND: Fatigue is prevalent after myocardial infarction (MI) and is a barrier to physical activity (PA). Because PA is an important health behavior in preventing or delaying recurrent MIs, examining the influence of biophysical markers and fatigue on PA is important as a prerequisite to developing effective interventions. OBJECTIVE: This study compared PA in 34 men and 38 women, aged 65 and older, 6-8 months post MI, and examined the influence of biophysiological measures and fatigue on PA in this sample. METHODS: Using a cross-sectional descriptive correlational design, adults completed a demographic form that included documentation of blood pressure, heart rate, height and weight; the Revised Piper Fatigue Scale (RPFS), and the Community Healthy Activities Model Program for Seniors Physical Activity Questionnaire for Older Adults, and blood collection for measurement of hemoglobin (Hgb), interleukin-6, and B-natriuretic peptide. RESULTS: There were no differences in frequency of PA between older men and older women; however, men reported a higher intensity of PA (p = .011). When controlling for sex, age, and biophysiological measures, the RPFS significantly explained 16% of the variance in the frequency of PA (p = .03), with no individual subscale serving as a significant predictor. The RPFS behavior/severity subscale explained 31% of the variance in energy expended on all PA (p < .001) and 40% of the variance in energy expended on moderate-intensity PA (p < .001). CONCLUSION: The older adults participating in this study did not participate in the recommended levels of PA, and fatigue significantly influenced PA post MI.