Related Experiment Video
Updated: Apr 20, 2026

Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity
Published on: March 7, 2019
Correlates of objectively measured physical activity in cardiac patients
Wonwoo Byun1, Cemal Ozemek1, Katrina Riggin1
11 Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND 58102, USA ; 2 Master of Public Health Program, North Dakota State University, Fargo, ND, USA ; 3 Clinical Exercise Physiology Program, Human Performance Laboratory, Ball State University, Muncie, IN 47306, USA ; 4 Cardiopulmonary Rehabilitation Program, Indiana University Health - Ball Memorial Hospital, Muncie, IN, USA ; 5 Department of Kinesiology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA ; 6 Center for Aging and Translational Research, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.
Abstract:
Cardiac patients would benefit from increasing their physical activity (PA) levels. Understanding of factors that influence cardiac patients' PA participation would benefit the development of effective interventions. Therefore, the purpose of this study was to determine correlates of objectively-measured PA in cardiac patients. Participants were 65 cardiac patients (74% male, 95% white), age 58.6±10.6 years. The amount of time spent in PA was measured by ActiGraph GT3X accelerometers for 7 days prior to joining cardiac rehabilitation programs (CRP). A total of 25 potential determinants of PA across multiple domains (demographic, clinical, psychosocial, and behavioral) were measured via self-reported questionnaire and clinical examinations. Backward elimination model selection procedures were performed to examine associations of potential determinants with total PA (min/day) and moderate-to-vigorous PA (MVPA) (min/day). Patients spent 153.8±62.8 and 8.4±8.1 min/day in total PA and MVPA, respectively. Across four domains, ten and five potential correlates were found to be significant in univariate analyses for MVPA and total PA, respectively. In the final model, functional capacity, PA readiness, and participation in regular exercise were positively associated with MVPA (R(2) =26.6%). Functional capacity and PA readiness were also positively associated with total PA (R(2) =15.9%). Future initiatives to increase PA levels in cardiac patients could be improved by considering patients' functional capacity, PA readiness, and exercise history in designing interventions.
Related Concept Videos
Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
Pathophysiology of Cardiac Performance
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...

