Nutrition Science and Everyday Application - beta v 0.1

548 ALICE CALLAHAN, PHD, HEATHER LEONARD, MED, RDN, AND TAMBERLY POWELL, MS, RDN
muscle and smaller proportion of fat than an unfit individual of the same weight. Although
habitual physical activity can promote a more healthful body composition, other factors like
age, gender, genetics, and diet contribute to an individual’s body composition. You can refer
back to Unit 7 for a detailed discussion on body composition, how it is measured, and how it
is used as an indicator for health.
THE BENEFITS OF PHYSICAL ACTIVITY
Regular physical activity is one of the best things you can do to achieve optimal health.
Individuals who are physically active for 150 minutes per week lower the risk of dying early
by 33 percent compared to those who are inactive. 3 The 2018 Physical Activity Guidelines for
Americans were issued by the Department of Health and Human Services (HHS) to provide
evidence-based guidelines to Americans aged three and older about how to improve health
and reduce chronic disease risk through physical activity. You can review the guidelines here,
including recommendations for children, adolescents, and adults. 4
Key Guidelines for Adults
• Adults should move more and sit less throughout the day. Some physical activity is better than
none. Adults who sit less and do any amount of moderate-to-vigorous physical activity gain some
health benefits.
• For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes)
to 300 minutes (5 hours) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes)
to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or
an equivalent combination of moderate- and vigorous-intensity aerobic activity. Preferably, aerobic
activity should be spread throughout the week.
• Additional health benefits are gained by engaging in physical activity beyond the equivalent of 300
minutes (5 hours) of moderate-intensity physical activity a week.
• Adults should also do muscle-strengthening activities of moderate or greater intensity and that
involve all major muscle groups on 2 or more days a week, as these activities provide additional health
benefits.
Source: 2018 Physical Activity Guidelines for Americans
Improving your overall fitness involves sticking with an exercise program on a regular
basis. If you are nervous or unsure about becoming more active, the good news is that
moderate-intensity activities, such as brisk walking, are safe for most people. Also, the health
advantages of becoming active far outweigh the risks. Physical activity not only helps to
maintain your weight, it also provides a wealth of benefits—physical, mental, and emotional.