Most adults should aim for at least 150 minutes of moderate-intensity cardio per week, or 75 minutes of vigorous-intensity cardio. That’s the baseline recommended by the World Health Organization, the American Heart Association, and the U.S. Department of Health and Human Services. But “at least” is doing real work in that sentence. Depending on your goals, the ideal amount could be quite different.
The Baseline: 150 Minutes Per Week
The standard guideline is a range, not a single number. For substantial health benefits, adults should get 150 to 300 minutes of moderate-intensity aerobic activity per week, or 75 to 150 minutes of vigorous-intensity activity, or some combination of both. A simple way to think about it: one minute of vigorous exercise counts roughly as two minutes of moderate exercise.
These numbers apply to adults of all ages, including those 65 and older. The CDC recommends that older adults also add at least two days of muscle-strengthening activities and exercises that improve balance, like walking heel-to-toe or standing from a seated position.
If 150 minutes sounds like a lot, it breaks down to just over 20 minutes a day, or 30 minutes five days a week. You don’t need to do it all at once. Shorter bouts spread throughout the day count toward the total.
How to Tell If You’re Working Hard Enough
The simplest way to gauge intensity is the talk test. During moderate-intensity exercise, you can hold a conversation but couldn’t sing along to a song. Think brisk walking, casual cycling, or a relaxed swim. During vigorous-intensity exercise, you can only get out a few words before needing to catch your breath. Running, fast cycling, and lap swimming typically fall here.
This matters because the weekly target changes based on intensity. If all your cardio is vigorous, you need half the time. If you mix intensities throughout the week, you can blend the two targets proportionally.
How Much Cardio for Weight Loss
The 150-minute baseline is designed for general health, not necessarily weight management. For weight loss or maintaining lost weight, the evidence points toward 300 minutes per week of moderate-intensity activity, which works out to about 45 minutes a day, six days a week, or an hour five days a week. The Mayo Clinic and federal guidelines both highlight this higher volume as the threshold where exercise starts making a meaningful difference on the scale.
That said, cardio alone is a slow path to weight loss without changes to what you eat. The real advantage of higher cardio volumes is that they create a larger energy deficit and improve the odds of keeping weight off long term.
How Much Cardio for Longevity
One of the more interesting findings in exercise science is that the relationship between cardio and lifespan isn’t a straight line. A large study published in the Journal of the American College of Cardiology, tracking over 55,000 adults, found that 1 to 2.4 hours of jogging per week, done 2 to 3 times at a slow or average pace, was the sweet spot for reducing mortality risk.
Jogging more than 2.5 hours per week, more than 3 times per week, or at faster paces didn’t improve survival compared to not jogging at all, suggesting a U-shaped curve where extreme volumes lose their benefit. That said, the same study still found significantly lower mortality risk even at the highest levels of running (over 176 minutes per week, 6 or more sessions), compared to being completely sedentary. So while more isn’t always better, it’s still better than nothing.
The practical takeaway: if your primary goal is living longer, moderate amounts of easy cardio a few times per week deliver most of the benefit. You don’t need to train for a marathon.
HIIT as a Time-Saving Option
If fitting in 150 to 300 minutes of steady cardio feels unrealistic, high-intensity interval training can compress the benefits into far less time. Research from McMaster University found that short sprint interval protocols produced similar improvements in endurance capacity and cellular fitness markers as much longer moderate-intensity sessions.
A typical HIIT session lasts about 20 minutes total: a 5-minute warm-up, 8 rounds of 30 seconds hard effort followed by 90 seconds of easy recovery, and a 5-minute cool-down. Another well-studied format, sometimes called the Norwegian 4×4 protocol, uses 4-minute hard efforts at near-maximum heart rate with 3-minute recovery periods between them.
Two or three HIIT sessions per week, combined with a couple of easier cardio days, is a practical way to hit your targets without spending an hour on a treadmill every day. Just keep in mind that HIIT is taxing on the body and shouldn’t make up every workout.
Cardio for Mental Health
Beyond heart health and weight, cardio has a direct effect on anxiety and mood. Research on women with major depressive disorder found that a single 30-minute session of moderate-intensity cycling significantly reduced anxiety compared to quiet rest, with the effect lasting at least 30 minutes after the workout ended.
Interestingly, harder exercise didn’t produce better results. The study found no linear relationship between intensity and anxiety reduction, meaning moderate effort was the most effective prescription. This is useful to know if you’re exercising specifically to manage stress or mood: a brisk walk or easy bike ride may do more for your mental state than an all-out sprint session.
When More Cardio Becomes Risky
For the vast majority of people, the risk of doing too much cardio is far smaller than the risk of doing too little. But extreme volumes do carry real concerns. Chronic endurance training at very high levels, the kind seen in competitive marathon runners and ultra-endurance athletes, can cause temporary heart damage that, repeated over years, may lead to thickening of the heart walls, scarring of heart tissue, and an increased risk of abnormal heart rhythms like atrial fibrillation.
People with underlying heart conditions, particularly hypertrophic cardiomyopathy or coronary heart disease, face a higher acute risk during intense exercise. Still, the Cleveland Clinic notes that even the long-term risk of atrial fibrillation from heavy exercise is small compared to the risks of being inactive. This is relevant mainly for people training at extreme volumes, not for someone doing 30 to 60 minutes most days of the week.
Combining Cardio With Strength Training
Every major health organization recommends pairing your weekly cardio with at least two sessions of resistance training that work all major muscle groups. A practical weekly layout for general health looks like 2 to 3 days of cardio and 2 to 3 days of strength training. If your primary goal is aerobic performance, like training for a race, keep your strength sessions on non-cardio days so you get the most out of both.
Strength training doesn’t replace cardio, but it fills in gaps that cardio can’t cover on its own: bone density, muscle mass, joint stability, and metabolic health as you age. The two work best as a pair.