Final answer:
Moderate-intensity physical activity, as per the 2018 Physical Activity Guidelines, allows for talking but not singing and includes activities like brisk walking. Adults should aim for 150 to 300 minutes of moderate-intensity activity per week for significant health benefits.
Step-by-step explanation:
According to the 2018 Physical Activity Guidelines established by the Department of Health and Human Services, moderate-intensity physical activity for most adults is defined as activities where individuals can talk but not sing during the exercise.
These guidelines suggest that for substantial health benefits, adults should aim for at least 150 minutes to 300 minutes per week of such activity. Examples of moderate-intensity activities include brisk walking, water aerobics, and slow-paced cycling. Furthermore, consistent engagement in physical activity is associated with numerous health benefits, including reducing the risk of chronic diseases such as heart disease and diabetes, improving bone density, and enhancing cognitive function.