National Guidelines for Physical Activity

Issues of Concern

Research has demonstrated that insufficient physical activity in all age groups not only increases all-cause mortality, cancer risk, serious falls, depression, and cognitive impairment but also contributes to metabolic disorders such as diabetes mellitus, hypertension, and dyslipidemia. Guidelines and strategies are needed to encourage people of all ages to intensify their level of physical activity.

Traditionally, continuous exercise at a moderate to vigorous intensity was recommended. Recent research, however, maintains the superiority of accumulated physical activity sessions performed throughout the day in short intervals.[4] Current guidelines state that bouts of moderate-to-vigorous physical activity promote health benefits regardless of the duration and, therefore, can count towards meeting overall exercise goals.[2] This replaces previous recommendations that exercise duration at a moderate-to-vigorous intensity level needs at least ten consecutive minutes for benefits to accrue.

Clinical Significance

Growing evidence shows a curvilinear dose-response association to suggest a positive relationship between the effects of exercise with improved bone health, stable weight status, and decreased incidence of 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, attributing reduced latency to sleep onset, increasing deep sleep, and enhancing concentration and learning ability.[5]

Table 1. Examples of Physical Activities and Intensity Type[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 5-17 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 perform aerobic exercises such as running, hopping, swimming, dancing, and bicycling at least 3 days a week. 
• Age-appropriate, muscle-strengthening exercises such as tree climbing, playground equipment participation, or games similar to tug-of-war type should be encouraged at least 3 days a week.
• Age-appropriate, bone-strengthening exercises, including weight-bearing activities such as running, jumping roping, tennis, and basketball, are also recommended at least 3 days a week. This is especially important to increase bone mass just before and during puberty.[7]

Recommendations for Adults (Ages 18-64 Years)

Adults who sit less and perform any amount of moderate to vigorous activity achieve some health benefits. Substantial benefits are observed with:

• Moderate-intensity (3 to 5.9 metabolic equivalents) aerobic exercise for 150 to 300 minutes, 75 to 150 minutes of vigorous-intensity (>6 metabolic equivalents) aerobic exercise, or an equivalent combination of MVPA averaged weekly.
• New evidence supports the value of total physical activity rather than the length of individual sessions. In addition, health benefits increase when the MVPA duration is exceeded by 3 to 5 times.[8]
• A general rule is that 2 minutes of moderate-intensity activity equals 1 minute of vigorous-intensity activity. A helpful estimate is a person performing moderate-intensity activities can talk but not sing, and someone doing vigorous-intensity activities cannot speak without difficulty.
• Adults should also engage in muscle-strengthening exercises such as weight-lifting or sit-ups at least 2 to 3 times weekly rather than on consecutive days.  
• The warm-up before and cool-down after exercise promotes microtear recovery in muscle fibers and prevents dizziness. This reduces the risk of injury.
• Increasing the amount of energy expenditure gradually over weeks to months is crucial.  

Recommendations for Older Adults (65 Years and Older)

High certainty evidence demonstrates an inverse dose-response association between the volume of aerobic exercise and the risk of physical function and mobility limitation in older adults, even frail individuals.[3]  Many older individuals have one or more chronic health conditions and benefit from regular physical activity. Balance training and fall prevention exercises should also be performed at least 3 times per week to reduce the risk of age-related function loss.[9] 

• According to their fitness level, older adults should perform multicomponent physical activity with aerobic and muscle-strengthening exercises.
• When 150 minutes of moderate-intensity aerobic activity per week cannot be tolerated, older adults should be as physically active as possible.

Recommendations for Pregnant and Postpartum Women 

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

• Women should be encouraged to perform at least 150 minutes of moderate-intensity aerobic activity weekly during pregnancy and following delivery.
• Aerobic activity is preferred over muscle-strengthening exercises multiple times per week.
• Women who were physically active before pregnancy can continue their activities as tolerated.
• Healthcare providers should be consulted regarding when and how to adjust physical activity during pregnancy and tailor exercise regimens to each woman's circumstances. 
• Activities that involve lying supine 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 or trauma should 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 perform moderate-intensity exercise (150-300 minutes) or vigorous-aerobic activity (75-150 minutes) weekly. They should also do muscle-strengthening exercises at least 2 or 3 times weekly.[11] Pre-exercise evaluation is required if they suffer from exercise-related health problems. 

Patients with diabetes should avoid resting for more than 2 consecutive days because the increased insulin sensitivity from exercising dissipates in 2 to 3 days and may affect serum glucose levels. Also, exercise-induced hypoglycemia is a known risk that should be considered, particularly when insulin secretagogues or insulin injections are used. Some specialists recommend abdominal insulin injections instead of injections in the arms to prevent hypoglycemia and avoid rapid absorption. Post-exercise, blood-glucose levels can remain lower 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, exercise plays a pivotal role in reducing the progression.[13] In osteoarthritis patients, new guidelines recommend low-impact aerobic conditioning and low, weight-bearing resistance exercises rather than inactivity.[14] 

Recommendations for People Living With Disabilities

Physical activity improves the quality of life in people with intellectual disability, multiple sclerosis, and spinal cord injury.[15] Evidence for those with chronic health conditions, including spinal cord injury, cerebrovascular accident, multiple sclerosis, clinical depression, schizophrenia, and attention-deficit/hyperactivity disorder (ADHD), suggest that physical activity is safe without contraindications or significant risks when appropriately supervised.[16][17] Wheelchair users should be encouraged to do light-intensity or high-intensity exercises that involve the upper body.

Exercise Precautions 

Physical activity should be performed safely and effectively. Ensuring safety precautions is a crucial recommendation of the national guidelines, and safety precautions should always be taken. 

• The current fitness level and health goal should determine the choice of physical activity.
• Increasing physical activity should be gradual as fitness improves.
• Generally, inactive people should begin 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 an activity program.
• Patients with asthma should be mindful of their environmental triggers, which might lead to exacerbations. Some specialists recommend indoor activities during cold weather and the spring allergy season if necessary.
• All patients should be mindful of high temperatures and humidity during the summer.
• Patients taking medications such as nitroglycerin or phosphodiesterase inhibitors must be cautious as these agents may cause hypotension if taken before physical activity.[18]
• Some anticholinergics to treat dementia or cognitive impairment may inhibit sweating and lead to hyperthermia or fatal heat stroke, especially in older individuals.[19]

Nursing, Allied Health, and Interprofessional Team Interventions

A sedentary lifestyle is associated with increased disease risk and all-cause mortality.[2] Healthcare providers, including clinicians, nurses, physical therapists, and occupational therapists, need to work together to encourage their patients to be physically activity and less sedentary.

The clinical nurse can score patient questionnaires about physical activity at preventive visits to identify those at risk of inactivity-related adverse outcomes. The clinical nurse and medical provider should educate patients on safe and practical ways to increase physical activity. Occupational and physical therapists can develop and implement rehabilitation programs focused on strengthening and improving the physical function of patients whose acute or chronic conditions limit their physical activity. 

All healthcare team members should educate patients about the incremental benefits of physical activity at every level. They can inform patients that even a slight increase in physical activity provides health benefits and that no threshold action level must be achieved before benefits begin.[2] 

The key message in all current guidelines is that 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 and ultimately improve healthcare outcomes.

Nursing, Allied Health, and Interprofessional Team Monitoring

The interprofessional team should develop programs aligned with the guidelines to help individuals achieve physical activity goals. Programs do not need to provide all the recommended activity goals for each patient. However, successful programs will meet the following criteria:[2] 

• They provide patient education consistent with the national physical activity guidelines.
• They include descriptions of types of activity that count toward meeting the guidelines.
• They advise patients on the benefits of stretching, warming up, and cooling down to perform physical activity safely and effectively.