Where the Guidelines Come From

The primary source of physical activity guidance in the United States is the Physical Activity Guidelines for Americans, published by the U.S. Department of Health and Human Services (HHS). The guidelines are developed through a systematic review of scientific evidence and are periodically updated — the most recent major edition was released in 2018. They cover adults, older adults, children, adolescents, and special populations including pregnant individuals and people with chronic conditions.

These guidelines inform recommendations from the Centers for Disease Control and Prevention (CDC), the American Heart Association (AHA), and other major health bodies. For a detailed plain-language breakdown of the adult targets, see our adult physical activity reference.

Primary U.S. guideline source Physical Activity Guidelines for Americans (HHS) (U.S. Department of Health and Human Services, 2018)
Adult aerobic target (moderate) 150–300 minutes per week (HHS Physical Activity Guidelines, 2nd Edition)
Adult aerobic target (vigorous) 75–150 minutes per week (HHS Physical Activity Guidelines, 2nd Edition)
Muscle-strengthening (adults) 2 or more days per week (HHS Physical Activity Guidelines, 2nd Edition)
Daily target for children (ages 6–17) At least 60 minutes of moderate-to-vigorous activity (HHS Physical Activity Guidelines, 2nd Edition)
Minimum bout length required None — accumulated movement counts (Updated in the 2018 guidelines revision)

Recommendations by Population Group

Adults (ages 18–64): The guidelines call for at least 150 to 300 minutes of moderate-intensity aerobic activity per week, or 75 to 150 minutes of vigorous-intensity activity, or an equivalent combination of both. Muscle-strengthening activities — such as resistance training or bodyweight exercises — involving all major muscle groups are recommended on two or more days per week. More activity generally yields greater health benefits, though any amount is better than none.

Older adults (65 and older): The aerobic and muscle-strengthening targets are the same as for younger adults. The guidelines add an emphasis on balance training to reduce fall risk, and recommend that older adults determine how much and what types of activity their fitness level and health conditions allow — ideally in consultation with a healthcare provider.

Children and adolescents (ages 6–17): The recommendation is at least 60 minutes of moderate-to-vigorous physical activity daily. This should include aerobic activity most days, plus muscle- and bone-strengthening activities at least three days per week. Physical habits vary meaningfully by life stage, and building movement routines early has documented long-term benefits.

Moderate-intensity activity

Exercise that noticeably increases heart rate and breathing but still allows a person to hold a conversation. Examples include brisk walking, water aerobics, and casual cycling.

Vigorous-intensity activity

Exercise that substantially raises heart rate and breathing, making sustained conversation difficult. Examples include running, swimming laps, and aerobic dance.

Muscle-strengthening activity

Exercise that causes muscles to work against resistance, such as weight training, resistance bands, or bodyweight exercises like push-ups. Recommended for all major muscle groups.

Aerobic activity

Sustained rhythmic movement that uses large muscle groups and elevates heart rate and oxygen use over time. It is the primary type of exercise addressed by the weekly minute targets.

Balance training

Exercises specifically designed to improve stability and reduce fall risk, particularly relevant for older adults. Examples include standing on one foot or tai chi.

Special populations: Pregnant and postpartum individuals without contraindications are generally encouraged to aim for at least 150 minutes of moderate-intensity aerobic activity per week. People with chronic conditions or disabilities should aim to meet adult guidelines when able, and should work with their care team to identify appropriate adaptations. Always consult a qualified healthcare professional before starting or significantly changing a physical activity program, especially if you have a chronic condition, are pregnant, or are returning to activity after injury or illness.

What the Evidence Shows

150–300 min

Weekly moderate aerobic activity for adults

Per the HHS Physical Activity Guidelines for Americans, 2nd Edition (2018).

60 min/day

Daily activity recommended for children ages 6–17

Includes aerobic, muscle-strengthening, and bone-strengthening activity across the week.

2+ days/week

Muscle-strengthening sessions for adults

Targeting all major muscle groups, per HHS guidelines.

The guidelines are grounded in evidence linking regular physical activity to reduced risk of cardiovascular disease, type 2 diabetes, several cancers, depression, and all-cause mortality. The aerobic targets reflect a threshold at which population-level benefits become consistently measurable across large, diverse studies.

Muscle-strengthening is included separately because its benefits — improved musculoskeletal health, metabolic function, and functional independence — are distinct from aerobic gains and require different types of effort. Research also supports physical activity's role in mood and cognitive health; the evidence on exercise and mental health is more nuanced than headlines often suggest.

Importantly, the 2018 guidelines dropped the earlier requirement that aerobic activity be performed in bouts of at least 10 minutes. Current evidence shows that accumulated movement throughout the day — even in shorter increments — contributes meaningfully to health. Activity also complements other preventive health behaviors: see recommended health screenings by age for the full picture of routine preventive care.

Hydration is a practical consideration for anyone increasing their activity level. Fluid needs during exercise depend on intensity, duration, and individual factors — a reference worth reviewing alongside any new movement routine.

This article is for general informational purposes only and is not a substitute for personalized medical advice. Consult a qualified healthcare provider for guidance specific to your health status and needs.