Changes in Physical Activity and Sedentary Behavior During Cardiac Rehabilitation

Area of Science:

• Cardiology
• Exercise Physiology
• Behavioral Science

Background:

• Cardiac rehabilitation (CR) is crucial for patients with acute coronary syndrome (ACS).
• Objective measurement of physical activity and sedentary behavior during CR is essential for optimizing patient outcomes.
• Current CR guidelines focus on exercise intensity, with less emphasis on the distribution of activity and sedentary time.

Purpose of the Study:

• To objectively quantify changes in moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SB) during and after a standard CR program.
• To assess the distribution patterns of MVPA and SB, not just the total time spent in each behavior.
• To provide insights for refining CR interventions to better promote cardiovascular health.

Main Methods:

• A prospective cohort study involving 135 patients with ACS who completed outpatient CR.
• Objective measurement of MVPA and SB using accelerometers before CR, immediately after CR, and at a 1-year follow-up.
• Analysis included the proportion of time spent in MVPA and SB, as well as the distribution (e.g., duration of bouts) of these behaviors.

Main Results:

• A small but significant increase in MVPA time (approximately 5 minutes) was observed during CR and maintained at 1-year follow-up.
• Sedentary behavior (SB) time decreased significantly (approximately 22 minutes) during CR and was maintained at 1-year follow-up.
• SB became more fragmented during CR, with more frequent breaks and shorter periods of sitting, a pattern sustained at 1-year follow-up. MVPA distribution did not change.

Conclusions:

• Standard CR leads to modest improvements in MVPA and more substantial improvements in reducing and fragmenting SB.
• Despite improvements, patients still exhibit low MVPA and high SB levels post-CR, posing cardiovascular risks.
• There is a clear need to develop tailored CR targets addressing both the amount and distribution of MVPA and SB to enhance long-term cardiovascular health.