Abstract
BACKGROUND: In this second section of our 2-part review on the role of physical activity (PA) and cardiorespiratory fitness (CRF) in preventing and treating atherosclerotic cardiovascular disease (CVD), we expand on topics covered in part 1, including a comparison of moderate-intensity continuous training versus high-intensity interval training, the beneficial role of PA and CRF in heart failure, potential mal-adaptations that may result from extreme endurance exercise regimens, and the incidence of cardiac arrest and sudden cardiac death during marathon running and triathlon participation. Further, we review the principles of exercise prescription for patients with known or suspected CVD, with specific reference to exercise modalities, contemporary guidelines, the minimum exercise training intensity to promote survival benefits, and long-term goal training intensities, based on age-, sex-, and fitness-adjusted targets. Finally, we provide practical "prescription pearls" for the clinician, including a simple rule to estimate metabolic equivalents (METs) during level and graded treadmill walking, research-based exercise training recommendations, using steps per day, MET-minutes per week, and personal activity intelligence to achieve beneficial treatment outcomes, as well as the heart rate index equation to estimate energy expenditure, expressed as METs, during recreational and leisure-time PA. SUMMARY: This review compares moderate-intensity continuous training and high-intensity interval training, examines the role of PA and CRF in managing heart failure, and discusses the cardiovascular risks associated with extreme endurance exercise. It also provides practical guidelines for exercise prescription tailored to patients with CVD, highlighting advanced exercise prescription strategies to optimize cardiovascular health. KEY MESSAGES: Physicians and healthcare providers should prioritize referring patients to home-based or medically supervised exercise programs to leverage the cardioprotective benefits of regular PA. For most inactive patients, an exercise prescription is essential for improving overall health.