| Publishing agency | U.S. Department of Health and Human Services (HHS) |
| Current edition | 2nd Edition (2018) (Physical Activity Guidelines for Americans, HHS, 2018) |
| Moderate aerobic target | 150–300 minutes per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Vigorous aerobic target | 75–150 minutes per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Muscle-strengthening frequency | 2 or more days per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Minimum bout duration required | None — all activity counts (Updated in 2018 edition; previous guideline required ≥10-minute bouts) |
The Federal Framework: Where These Guidelines Come From
The Physical Activity Guidelines for Americans are published by the U.S. Department of Health and Human Services (HHS). The guidelines are grounded in systematic reviews of the scientific literature and are updated periodically — the second edition was released in 2018. They represent the federal government's official evidence-based recommendations for how much and what kinds of physical activity support health across life stages.
The guidelines apply to adults aged 18–64, with separate guidance for older adults (65+), children, pregnant individuals, and people with chronic conditions. This article focuses on the core adult framework.
| Publishing agency | U.S. Department of Health and Human Services (HHS) |
| Current edition | 2nd Edition (2018) (Physical Activity Guidelines for Americans, HHS, 2018) |
| Moderate aerobic target | 150–300 minutes per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Vigorous aerobic target | 75–150 minutes per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Muscle-strengthening frequency | 2 or more days per week (Physical Activity Guidelines for Americans, 2nd Ed.) |
| Minimum bout duration required | None — all activity counts (Updated in 2018 edition; previous guideline required ≥10-minute bouts) |
Core Aerobic Activity Targets
For meaningful health benefit, the guidelines recommend that adults accumulate at least 150 to 300 minutes per week of moderate-intensity aerobic activity, or 75 to 150 minutes per week of vigorous-intensity aerobic activity — or an equivalent combination of both. These are weekly targets, not daily mandates.
Moderate intensity means activity that noticeably increases heart rate and breathing but still allows you to hold a conversation — brisk walking is a common example. Vigorous intensity raises heart rate substantially and makes sustained conversation difficult; jogging and cycling uphill fall into this category. Walking as a form of exercise is examined in depth in a companion article, including where it fits within these intensity levels.
A key update in the 2018 edition: any bout of activity counts, regardless of duration. The previous requirement that bouts last at least 10 minutes was removed based on evidence that shorter sessions also confer benefit when accumulated throughout the day.
150–300 min
Weekly moderate-intensity aerobic activity target
Per the 2018 Physical Activity Guidelines for Americans, HHS — the range representing minimum benefit to greater benefit.
~53%
U.S. adults meeting aerobic activity guidelines
According to CDC National Health Interview Survey data, roughly half of American adults meet federal aerobic activity targets.
2 days/week
Minimum muscle-strengthening sessions recommended
The 2018 HHS guidelines recommend strength training targeting all major muscle groups at least twice weekly.
Muscle-Strengthening: The Second Pillar
Beyond aerobic movement, the guidelines call for muscle-strengthening activities on two or more days per week, targeting all major muscle groups: legs, hips, back, abdomen, chest, shoulders, and arms. Examples include resistance training, bodyweight exercises, and heavy gardening or digging.
Strength training is often underemphasized in public messaging, yet it plays a distinct role in preserving lean mass, supporting bone density, and reducing fall risk — factors that become increasingly important with age. The guidelines do not specify the number of sets or repetitions, but public health institutions generally describe working muscles to the point of fatigue as a practical benchmark.
This second pillar complements the aerobic targets rather than substituting for them. Both components independently contribute to long-term health outcomes, including reduced risk of cardiovascular disease, type 2 diabetes, and certain cancers.
Moderate-intensity activity
Physical movement that increases heart rate and breathing noticeably but still allows the person to speak in full sentences. Examples include brisk walking, water aerobics, and casual cycling.
Vigorous-intensity activity
Exercise that substantially elevates heart rate and breathing, making it difficult to say more than a few words without pausing. Examples include jogging, running, and aerobic dancing.
MET (Metabolic Equivalent of Task)
A standard unit used to express the energy cost of physical activities relative to sitting at rest. Moderate activity is generally defined as 3–6 METs; vigorous activity exceeds 6 METs.
Muscle-strengthening activity
Exercise that works muscles against resistance — such as free weights, resistance bands, or bodyweight — to build and maintain strength and mass across major muscle groups.
Sedentary behavior
Any waking activity characterized by very low energy expenditure while sitting, reclining, or lying down. Prolonged sedentary time is associated with adverse health outcomes independent of overall activity levels.
Sedentary Behavior and the Broader Picture
The 2018 guidelines added explicit language about sedentary behavior for the first time: adults should move more and sit less. Research has shown that prolonged sitting carries independent health risks, even in people who meet weekly activity targets. What extended sedentary time does to the body is explored in greater detail in a related article.
Meeting the activity guidelines is best understood as part of a broader preventive health picture. Regular movement pairs with other health behaviors — sleep, nutrition, stress management — as described in habits that support preventive health across decades. It also aligns with routine preventive screenings; see recommended health screenings by age and sex for a complementary reference.
Guidelines Apply Differently to Older Adults
Adults aged 65 and older follow the same core aerobic and muscle-strengthening targets, but the HHS guidelines add a third component: balance training to reduce fall risk. Older adults with chronic conditions are advised to be as physically active as their abilities and conditions allow, and to consult a healthcare provider when planning a new activity routine.
This article is for general informational purposes only and does not constitute medical advice. Individuals with chronic health conditions, recent surgery, or other clinical concerns should consult a qualified healthcare professional before beginning or significantly changing a physical activity routine.