You’re considered physically active if you get at least 150 minutes of moderate-intensity aerobic activity per week, or at least 75 minutes of vigorous-intensity activity, plus two days of muscle-strengthening exercise. Those are the benchmarks set by the World Health Organization and echoed by the CDC. But the full picture is more nuanced than a single number, because intensity matters, age changes the requirements, and even everyday movement counts more than you might think.
The Weekly Minimums for Adults
For adults aged 18 to 64, meeting the “physically active” threshold means hitting one of these targets each week:
- 150 to 300 minutes of moderate-intensity aerobic activity (like brisk walking), or
- 75 to 150 minutes of vigorous-intensity aerobic activity (like running), or
- An equivalent combination of both
On top of that aerobic baseline, you need muscle-strengthening activities on two or more days per week that work all major muscle groups: legs, hips, back, abdomen, chest, shoulders, and arms. That could be weightlifting, resistance bands, bodyweight exercises like push-ups and squats, or heavy gardening. Without the strength component, you’re not fully meeting the guidelines even if your cardio numbers look great.
A common way to structure this: 30 minutes of brisk walking five days a week, plus two sessions of resistance training. Or three 25-minute runs per week with two days of strength work. The minutes don’t need to happen in a single block. Shorter bouts throughout the day count toward your total.
How Intensity Is Measured
The difference between moderate and vigorous activity comes down to how hard your body is working. There are two practical ways to gauge this.
Heart rate is the most accessible measure. Moderate intensity falls between 50% and 70% of your maximum heart rate. Vigorous intensity sits between 70% and 85%. A rough estimate of your maximum heart rate is 220 minus your age, so a 40-year-old would aim for roughly 90 to 126 beats per minute for moderate effort and 126 to 153 for vigorous effort.
Researchers also use a unit called a MET, which compares the energy you burn during an activity to the energy you burn sitting still. Moderate-intensity activities fall between 3 and 5.9 METs. Anything at 6 METs or above is vigorous. You don’t need to calculate METs yourself, but they’re the reason official guidelines classify specific activities the way they do. A simple talk test works too: during moderate activity, you can talk but not sing. During vigorous activity, you can only say a few words before needing a breath.
What Counts as Moderate or Vigorous
Moderate-intensity activity doesn’t require a gym. Brisk walking (roughly 3 to 4 miles per hour), mowing the lawn with a push mower, raking leaves, mopping, vacuuming, casual cycling, and water aerobics all qualify. The key is sustained effort that noticeably raises your heart rate and breathing.
Vigorous-intensity activities include running, swimming laps, singles tennis, hiking uphill, cycling at 10+ miles per hour, and high-intensity interval training. Because vigorous activity demands roughly twice the effort of moderate activity, one minute of vigorous exercise counts as two minutes of moderate exercise when you’re mixing both in a week.
Requirements for Children and Older Adults
Children and adolescents aged 5 to 17 need more activity than adults: at least 60 minutes per day of moderate-to-vigorous intensity physical activity, mostly aerobic. On at least three of those days, the activity should include vigorous aerobic exercise plus exercises that strengthen muscle and bone, like jumping, climbing, or playing sports.
Older adults aged 65 and up follow the same 150-to-300-minute aerobic baseline as younger adults, but with an added emphasis on balance and functional training. The WHO recommends varied, multicomponent physical activity that includes balance exercises and strength training at moderate or greater intensity on three or more days a week. This is specifically aimed at preventing falls and maintaining the ability to perform everyday tasks independently.
Pregnant and postpartum women have a slightly different target: at least 150 minutes of moderate-intensity aerobic activity per week, without the vigorous-intensity option.
Sedentary vs. Inactive: They’re Not the Same
A common misconception is that “sedentary” and “physically inactive” mean the same thing. They don’t. Physical inactivity means not meeting the recommended activity guidelines. Sedentary behavior refers specifically to time spent sitting, reclining, or lying down while awake, at very low energy expenditure (1.5 METs or below). Think desk work, watching TV, or scrolling your phone.
Here’s the important part: you can be both active and sedentary. Someone who runs for 30 minutes each morning but sits at a desk for the remaining 10 waking hours meets the activity guidelines and is classified as physically active, yet still accumulates a high volume of sedentary time. Both dimensions matter independently for health, which is why breaking up prolonged sitting throughout the day has value even if your weekly exercise totals are solid.
Where Step Counts Fit In
Step counts offer a simpler way to think about activity levels, especially if you wear a fitness tracker. A widely used graduated step index classifies adults into five categories:
- Under 5,000 steps per day: sedentary
- 5,000 to 7,499: low active
- 7,500 to 9,999: somewhat active
- 10,000 to 12,499: active
- 12,500 and above: highly active
The sedentary category was later refined further, with fewer than 2,500 steps classified as “basal activity” and 2,500 to 4,999 as “limited activity.” These thresholds aren’t a perfect substitute for the minutes-based guidelines since they don’t capture intensity or non-walking exercise like swimming or cycling, but they provide a useful daily benchmark.
Everyday Movement Adds Up
Formal exercise, the kind you plan and schedule, isn’t the only activity that matters. The energy you burn through everyday movement (standing, walking around the house, climbing stairs, fidgeting, cleaning, cooking) represents a significant and often underestimated portion of your daily calorie expenditure. For people who don’t do structured workouts, this informal movement makes up nearly all of their physical activity energy expenditure.
These low-level activities don’t typically reach moderate or vigorous intensity, so they won’t check the box for official guidelines on their own. But they meaningfully increase total energy expenditure above resting levels, and they accumulate over hours. Someone who stands and walks frequently throughout the day burns substantially more energy than someone sitting for the same period, even if neither person exercises. For people who struggle with structured exercise, increasing everyday movement (taking stairs, walking while on phone calls, doing housework more frequently) offers a realistic starting point with high adherence over time.
Why the Minimum Matters
Meeting even the lower end of the guidelines produces measurable health benefits. Adults who get the recommended 150 minutes of moderate or 75 minutes of vigorous activity per week can reduce their risk of dying from cardiovascular disease by 22% to 31%. People who fall below those thresholds, classified as insufficiently active, see the greatest relative improvement by adding even modest amounts of movement to their routine.
Going beyond the minimum provides additional benefits. The WHO notes that increasing moderate activity above 300 minutes or vigorous activity above 150 minutes per week yields further health gains. But the steepest drop in risk happens when someone moves from inactive to meeting the baseline recommendation. If you’re currently doing very little, even getting partway to 150 minutes per week is a meaningful improvement.