How Long Should Cardio Workouts Last to Be Effective?

Few things pack a healthy punch quite like a cardio workout: Your muscles, including your heart, are working hard.

The Physical Activity Guidelines for Americans are pretty clear that when it comes to aerobic exercise, "any amount is helpful, generally more is better, and many Americans are too sedentary," Janet Hamilton, CSCS, MA, an exercise physiologist and running coach, tells LIVESTRONG.com.

However, if you're after specific benefits like heart health, weight loss or general fitness, you may need to be more purposeful in how you package your cardio workouts.

So if you're wondering, "how long should I do cardio?," here are some ways to structure your weekly cardio workouts according to your goal.

Activities that involve continuous movement and the use of large muscle groups to raise your heart rate are one of the best ways to keep your cardiovascular system — your heart and blood vessels — healthy.

Higher levels of physical activity are associated with a lower risk of cardiovascular disease. People who reported the most physical activity had a 60 percent lower risk of heart disease than their less-active peers, according to a January 2021 study in ​PLOS Medicine​. But researchers found that even increasing your daily activity by as little as 1,000 steps may lower your risk of heart disease.

So how long should a cardio workout be for heart health? Aim for 30 minutes of moderate-intensity cardio per day, five days per week.

"That's the bare minimum if someone wants to have the minimum average risk of cardiovascular disease," Paul Krieger, RD, CPT, a registered dietitian and certified personal trainer with Life Time who specializes in endurance programming, tells LIVESTRONG.com.

For even greater heart-health benefits, the American Heart Association (AHA) recommends upping your weekly activity total to 300 minutes.

Choose any form of cardio exercise that you enjoy. Walking is a great choice and tends to be the most accessible, but other options include using the elliptical, cycling, rowing, jogging/running, swimming, skiing, hiking, pickleball and even dancing.

Whichever activity you land on, aim to move at a moderate intensity. You can still carry on a conversation at this intensity, but it should be challenging.

"If you're not breathing any harder than you were at rest, you're probably not working quite hard enough to get a benefit," Hamilton says.

As you gain fitness, feel free to add bouts of higher-intensity cardio to your routine. You won't be able to manage saying more than a few words — if any — at higher intensities.

There's a bit of overlap between exercising for heart health and general fitness. After all, a stronger heart contributes to fitness.

However, there is a slight difference between the two: "Heart health refers to building enough cardiovascular resilience to perform normal daily activities without getting winded, which would also help reduce the incidence of many chronic diseases," Krieger says.

Meanwhile, general fitness involves building enough cardiovascular capacity to enjoy moderately strenuous activities, such as running, hiking with a pack, swimming and sports.

If that's your goal, you'll want to gradually ramp up the amount of time you spend doing aerobic activity. Aim to add about 10 percent per week.

"That may not be appropriate for all, but it's a pretty safe starting point," Hamilton says.

So, if you're currently getting the weekly 150 minutes of moderate-intensity cardio recommended by the Physical Activity Guidelines for Americans, strive for 165 minutes the following week.

"If you want to build the stamina portion of your fitness, increase the longest workout first," Hamilton says. (Stamina refers to physical and/or mental capacity to sustain a prolonged effort.) The following week, add to your medium-length workouts. After that, add to the short workouts, and repeat.

Easy- and moderate-intensity cardio workouts take time, so if stamina isn't a must-have, you may be able to save time with more intense forms of cardio.

For example, high-intensity interval training (HIIT) — alternating bouts of all-out effort with recovery periods — is a great way to build fitness.

Thanks to the high-intensity intervals, the total workout can be pretty short — about 20 minutes — while still being effective. In fact, the findings from a March 2021 review in ​The Journal of Physiology​ suggest that HIIT may offer similar improvements in cardiovascular fitness as traditional forms of cardio.

"If you're doing 45 minutes, you're probably working at a moderate intensity," Kriegler says.

According to the AHA, cardio offers many handy benefits, like lowering blood pressure, improving sleep and brain health and slashing your risk for chronic health conditions. But aiding weight loss? Not so much.

The minimum guidelines for aerobic activity (150 minutes per week), for example, may be enough to improve heart health, but they're generally inadequate for shedding pounds without calorie restriction, per a July-August 2018 review in ​Progress in Cardiovascular Diseases​.

One reason is the sheer amount of time and effort it takes to burn a significant number of calories.

For example, a brisk, 30-minute walk done at a pace of 17 minutes per mile only burns between 107 and 159 calories, according to estimates from Harvard Health. That amount may help you achieve a healthy calorie deficit for weight loss, but research suggests you need a greater calorie burn to see meaningful weight loss from exercise.

In a March 2013 study in ​Obesity​, people living with overweight or obesity who burned 400 calories per workout five times per week lost 4.3 percent of their body weight over 10 months. Those who burned 600 calories per workout (also five times per week) lost 5.7 percent of their body weight. Neither group reduced their calorie intake.

To see a similar calorie burn, you would have to walk briskly for two-and-a-half to nearly four hours, according to estimates via Harvard Health. Or, you would have to increase your intensity: Running for 30 minutes at a pace of 10 minutes per mile burns between 420 and 495 calories.

The reality is that many people can't sustain a workout routine that burns at least 400 calories a session, five days per week.

Ultimately, nutrition is more important for weight loss than the amount or type of cardio you do, Kriegler says.

Here's one way to think about it: The time you have to grapple with food choices during the day far exceeds the time you have available for exercise. Even if you exercise for one hour, that still leaves 15 hours (not including sleeping time). Those 15 hours are filled with opportunities to make dietary decisions.

"You're almost better off skipping a workout if that means you can spend that time on meal prep," Kriegler says, when considering just weight loss.

All of this isn't to say that cardio can't or shouldn't be part of your routine if you're trying to lose weight. Aside from being a boon for heart health, cardio can contribute to your weekly calorie deficit.

Speaking strictly in terms of calories, you'll likely burn more per minute of HIIT than low- or moderate-intensity cardio. You may also burn more calories from fat, provided the exercise sessions are equal in length.

For example, a 30-minute cardio workout done at a low intensity will burn approximately 200 calories overall, with 120 calories from fat, according to the American Council on Exercise (ACE). But if you bump up that 30-minute workout to a high-intensity effort, you'll burn roughly 400 calories, with 140 calories from fat.

However, most of us can't manage many high-intensity workouts during the week — and experts don't recommend doing them every day, because your body needs time to rest in between.

While HIIT burns more calories, low- and moderate-intensity cardio is easier to do most days of the week, so it might be the ideal choice for a sustainable cardio routine. Mix in high-intensity bursts to add challenge and variety.

Kriegler recommends doing at least 80 percent of your cardio at a low-to-moderate intensity; the final 20 percent at higher intensities. Beginners should spend a few weeks building up to that volume at a low-to-moderate intensity. Then, work on increasing your intensity.