Final answer:
Healthy adults should do at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity per week, with additional health benefits for activity beyond 300 minutes of moderate-intensity per week.
Step-by-step explanation:
According to the 2018 Physical Activity Guidelines for Americans, issued by the Department of Health and Human Services (HHS), healthy adults should engage in at least 150 minutes a week of moderate-intensity physical activity or 75 minutes a week of vigorous-intensity physical activity. Moderate-intensity exercises are defined as those where you can talk but not sing during the activity, while vigorous-intensity exercises are those where you cannot say more than a few words without pausing for a breath.
The guidelines also recommend that for substantial health benefits, the activity should be spread throughout the week. Moreover, engaging in physical activity beyond 300 minutes a week of moderate-intensity can provide additional health benefits, especially in regards to weight loss and weight maintenance. It's also advised for adults to include muscle-strengthening activities on two or more days a week as these activities bring additional health benefits.