Continuing Education Activity

Regular physical activity is essential for maintaining good health and an adequate quality of life. Physical activity has health benefits for everyone regardless of age, current fitness level, or underlying clinical conditions. Physical activity is linked with positive health outcomes that can start accumulating immediately after doing physical activity. Still, most Americans do not meet the key guidelines for aerobic and muscle-strengthening activity. This activity reviews the current national guidelines for physical activity outlined by the U.S. Department of Health and Human Services in 2018 with supplemental recommendations and guidelines from the World Health Organization (WHO) 2020 Guidelines for physical activity and sedentary behavior.

Objectives:

• Review the health benefits associated with increased physical activity.
• Outline the United States national guidelines for physical activity.
• Identify differences in physical activity recommendations for special populations, such as pregnant women, people living with chronic diseases, and the elderly.
• Explain the role of an integrated interprofessional team in helping the population meet key guidelines for physical activity in the United States.

Definition/Introduction

The emphasis on physical activity goes back to 3000 B.C. when it was the quintessential principle of daily living and proper diet. Regular physical activity is essential for maintaining good health and an adequate quality of life. Physical activity has health benefits for everyone regardless of age, current fitness level, or underlying clinical conditions. Physical activity is linked with positive health outcomes that can start accumulating immediately after doing physical activity.

Sedentary behavior is characterized by low levels of energy expenditure (<1.5 metabolic equivalents), including leisure time while sitting, reclining, or laying down.[1] According to U.S. National Health and Nutrition Examination Survey, children and adults spend an average of 7.7 hours per day being sedentary. The majority of the American population does not meet the minimum requirement for aerobic and muscle-strengthening activity.

This lack of physical activity is associated with poor quality of life, increased risk of major medical illnesses, and an increased cost of healthcare in the United States. Consequently, the U.S. Department of Health and Human Services published guidelines with an updated edition in 2018 to help decrease physical inactivity and increase patient health benefits.[2] 

The World Health Organization (WHO) also released updated guidelines in 2020 regarding physical activity and sedentary behavior in an effort to increase global awareness about the lack of physical activity and associated health consequences.[3] 

This article reviews the recommendations provided in these guidelines in a clear and concise form to help promote better compliance with their key recommendations.

Issues of Concern

Recent research has demonstrated that insufficient physical activity in all age groups leads to increased all-cause mortality, cancer risk, metabolic disorders such as diabetes mellitus, hypertension, dyslipidemia, falls among the elderly, depression, and cognitive impairment. Therefore, there is a need to implement guidelines and strategies to enable people of all ages to intensify their investment in physical activity.

Traditionally, continuous exercise at a moderate to vigorous intensity was the primary recommendation. Current research, however, clearly identifies the superiority of accumulated "bouts" of physical activity performed throughout the day in short intervals.[4] 

The current guidelines state that "bouts" of moderate-to-vigorous physical activity promote health benefits regardless of the duration and, therefore, can count towards meeting the key guideline goals.[2] This is in contrast to the previous recommendations where the exercise duration at a moderate-to-vigorous intensity level needed at least 10 minutes to count.

Clinical Significance

There is growing evidence with curvilinear dose-response association to suggest the positive effects of exercise, such as improved bone health, stable weight status, and decreased incidence of cancers such as colorectal, breast, endometrial, and lung cancer.

Physical activity also ameliorates insulin resistance and obesity and is a significant risk modifier in cerebrovascular disease. Improvement in sleep quality and cognitive function is well documented that can be attributed to reduced latency to sleep onset, increased deep sleep, and enhanced concentration and learning ability.[5]

Table 1. Types of Physical Activities with Intensity[6]

National Guidelines for Physical Activity Published by the U.S. Department of Health and Human Services[2]

The key guidelines published by the U.S. Department of Health and Human Services in 2018 (2nd edition) for physical activity are summarized below. 

Recommendations for Children and Adolescents (Ages 5 through 17 years)

 An average of 60 minutes or more per day of enjoyable moderate-to-vigorous physical activity (MVPA) is recommended with the following distribution:

• Children and adolescents should be encouraged to do aerobic activities such as running, hopping, swimming, dancing, and bicycling at least three days a week. 
• Age-appropriate muscle strengthening exercises such as climbing trees or playground equipment and tug-of-war should be encouraged at least three days a week.
• Age-appropriate bone strengthening (weight-bearing) exercises such as running, jumping rope, tennis, and basketball are also recommended at least three days a week. This remains especially important because of the gain in bone mass just before puberty.[7]

Recommendations for Adults (Ages 18 through 64 years)

Per recently updated guidelines, adults who sit less and perform any amount of moderate to vigorous activity achieve health benefits. Substantial health benefits are observed with:

• Average weekly moderate intensity (3 to 5.9 metabolic equivalents) aerobic exercises for 150-300 minutes OR 75 to 150 minutes of vigorous-intensity (>6 metabolic equivalents) aerobic exercises OR an equivalent combination of MVPA.
• New evidence supports the value of total physical activity rather than bout length. In addition, health benefits become more extensive if we exceed the MVPA duration by 3 to 5 times the recommended.[8]
• A general rule is that 2 minutes of moderate-intensity activity is equivalent to 1 minute of vigorous-intensity activity. Also, we can assume that person performing moderate-intensity activity can talk but not sing, and a person doing a vigorous-intensity activity cannot speak without difficulty.
• Adults should also engage in muscle-strengthening exercises such as dumbbells, weight-lifting, and sit-ups at least 2-3 times a week rather than on consecutive days.  
• To reduce the risk of injury, cooling-down or warming up before exercise helps promote micro-tear recovery in muscle fibers and prevent dizziness.
• It is crucial to increase the amount of energy expenditure gradually over weeks to months.  

Recommendations for the elderly (65 years and above)

There is high certainty evidence demonstrating an inverse dose-response association between volume of aerobic exercise and risk of physical function and mobility limitation in older adults, even those who are frail.[3]  Most elderly patients have one or more chronic health conditions, and thus physical activity offers multiple benefits. 

Although they are recommended to engage in weekly physical activity as adults, balance training and fall prevention exercises should also be performed more than three times a week to reduce the risk of age-related loss of function.[9] 

• Older adults should perform multicomponent physical activity with aerobic and muscle-strengthening activities according to their fitness level.
• When 150 minutes of moderate-intensity aerobic activity a week cannot be tolerated, the older adult should be encouraged to be as physically active as their condition allows.

Recommendations for Pregnant and Postpartum Women 

Moderate-intensity physical activity is associated with improved cardiorespiratory fitness and reduced gestational and postpartum weight gain.[10] 

• Women should be motivated to do at least 150 minutes of moderate-intensity aerobic activity a week during pregnancy and postpartum.
• Preferably, aerobic activity should be performed, and it should be spread throughout the week.
• Women who were physically active before pregnancy can continue these activities as tolerated.
• Health care providers should be consulted regarding when and how physical activity during pregnancy should be adjusted. 
• In general, activities that involve lying on the back and increasing intrabdominal pressure, such as sit-ups and leg raises, should be avoided after the first trimester of pregnancy.
• Contact or collision sports and activities with a high risk of falling/trauma should also be avoided. 

Recommendations for People Living with Chronic Health Conditions 

Inactivity should be avoided. Adults with chronic diseases such as type 2 diabetes, hypertension, cancer, osteoarthritis, and HIV, are encouraged to do at least 150 to 300 minutes a week of moderate-intensity or 75 to 150 minutes a week of vigorous aerobic activity. They should also do muscle strengthening exercises at least 2 or 3 times a week.[11] Pre-exercise screening is required if they suffer from exercise-related health problems. 

Patients with diabetes should avoid rest of more than two days as the increased insulin sensitivity by exercise dissipates in 2-3 days. Also, exercise-induced hypoglycemia should be taken into consideration, particularly when insulin secretagogues or insulin injections are used. Some recommend injection into the abdomen instead of the arms to prevent hypoglycemia to avoid rapid insulin absorption. Post-exercise, blood glucose levels can be lowered for up to 48 hours.[12] High-intensity exercises should be avoided in patients with severe retinopathy and autonomic neuropathy. 

In patients with pre-hypertension, lifestyle modification plays a pivotal role in reducing the progression.[13] In osteoarthritis patients, new guidelines recommend low-impact aerobic exercises and low-weight bearing resistance exercises rather than inactivity.[14] 

Recommendations for People Living with Disabilities

Physical activity improves life quality in people with intellectual disability, multiple sclerosis, and spinal cord injury.[15] Reviewed evidence in the health conditions, including spinal cord injury, cerebrovascular accident, multiple sclerosis, clinical depression, schizophrenia, and attention deficit hyperactivity disorder (ADHD,) suggest that physical activity is deemed safe without contraindications, with no significant risks, and is appropriate if supervised.[16][17] Wheelchair users should be encouraged to do light-intensity or high-intensity exercises that involve the upper body.

Exercise Precautions 

It is essential to perform physical activity safely and effectively. Ensuring safety precautions is a key recommendation of the national guidelines and should be followed at all times. 

• The choice of physical activity should be determined by the current fitness level and health goal.
• Increments in physical activity should be made gradually
• As a general rule, inactive people should start with low-intensity exercises and gradually increase duration or frequency, preferably over multiple weeks.
• Activity-specific precautions should be followed with appropriate gear and sports equipment.
• People with chronic medical conditions should consult a health care professional or a physical activity specialist before starting any activity program.
• Patients with asthma should be mindful of their environmental triggers and their potential asthma exacerbation when physical activity is conducted in such environments. Some specialists recommend indoor activities for these patients during cold weather and the spring season. 
• All patients should be mindful of high temperatures and humidity during the summer.
• Patients taking medications such as nitroglycerin or phosphodiesterase inhibitors are advised to be cautious as these agents may cause hypotension if taken before physical activity.[18]
• Some anticholinergics used in dementia or cognitive impairment may inhibit sweating and lead to hyperthermia or fatal heat stroke, especially in the elderly.[19]

Nursing, Allied Health, and Interprofessional Team Interventions

A sedentary lifestyle is associated with increased disease risk and all-cause mortality.[2] It is essential for health care providers, including nurses, physical therapists, and occupational therapists, to assess and encourage physical activity and decrease the number of sedentary hours.

Patient questionnaires about physical activity should be provided at every preventive visit by the clinical nurse to identify those at the highest risk of inactivity-related adverse outcomes. The clinical nurse and medical provider should educate patients on ways to safely increase physical activity levels to ensure patient compliance. Occupational and physical therapists should implement safe and effective rehabilitation programs focused on strengthening and increasing the physical function of all patients.

The healthcare team should educate the patient about the incremental benefits of physical activity at every level. The patient should be taught that even a small increase in physical activity can provide health benefits and that no threshold level of action must be achieved before benefits begin.[2] 

The key message in all guidelines is that any amount of physical activity is better than inactivity. Moving more and sitting less throughout the day is the recommended motto and should be promoted by the healthcare team. A well-integrated interprofessional team of clinical providers can significantly reduce inactivity-related chronic diseases in the United States and improve health care outcomes. [Level 5]

Nursing, Allied Health, and Interprofessional Team Monitoring

Developing programs consistent with the guideline to help individuals achieve physical activity goals is essential to the interprofessional team of health care providers. Programs do not need to provide all of the recommended activity goals for the individual. However, programs considered consistent with the national guidelines meet the following criteria:[2] 

• They provide patient education consistent with the national physical activity guidelines.
• They add episodes of activity that can count toward meeting the key guidelines.
• They include stretching or warming up and cooling down to help patients perform the physical activity safely and effectively.