Final answer:
b) 150 minutes According to CDC and HHS guidelines, Marcus should engage in at least 150 minutes of moderate-intensity physical activity each week for substantial health benefits.
Step-by-step explanation:
The Centers for Disease Control and Prevention (CDC) and the U.S. Department of Health and Human Services (HHS) recommend for a healthy adult, such as a 55-year-old man, to engage in at least 150 minutes of moderate-intensity physical activity each week. Moderate-intensity activities are those during which a person can talk but not sing. These exercises offer numerous health benefits, including increased life expectancy, stronger immune system, improved cognitive ability, and better psychological well-being. It's also recommended to spread out the aerobic activity throughout the week and to include muscle-strengthening activities on 2 or more days per week for additional benefits.
The Centers for Disease Control and Prevention (CDC) recommends that Marcus, as a healthy 55-year-old man, should engage in at least 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) per week of moderate-intensity aerobic activity. This can include activities like brisk walking, bicycle riding, or swimming. Marcus can also choose to do 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) per week of vigorous-intensity aerobic activity if he prefers activities like running or playing basketball.