How Many Hours Of Exercise A Week Should I Do? 3 Key Factors

We'll explore the recommended amount of exercise needed to improve your general health and prevent disease, as well as how many hours of exercise you should do to lose weight.

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Some of the most common questions beginners ask when embarking on a fitness program or when trying to evaluate if they’re doing enough exercise is, “How much exercise do I need?” or, how many hours of exercise a week to lose weight?”

Knowing how much exercise per week you need to do will help ensure you are on track to meet your fitness and health goals. The number of hours you should exercise per week will indeed depend on your fitness goals and current fitness level.

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How Many Hours of Exercise A Week Do I Need to Do?

Several factors will influencethe amount of exercise you should do weekly.

Your primary fitness goal impacts the number of minutes of exercise per week recommended.

Additionally, the type of exercise you are doing and the intensity level also play a significant role in exercise prescription.

Let’s look at each of these factors.

Exercise Intensity

In terms of exercise intensity, the more vigorous your workouts, the fewer minutes or hours you need to work out per week in order to meet the recommended guidelines for physical activity.

In fact, even if you are a competitive athlete and looking to far exceed the minimums for health and disease prevention, high-intensity or vigorous workouts still take much more of a toll on the body, so the number of hours of exercise you do per week should be less than if you were primarily doing only moderate intensity exercise. 

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Doing too much exercise can lead to overtraining syndrome, which will not only compromise your athletic performance but can be deleterious to your overall health, compromise your immune system, disrupt sleep and appetite, cause mood issues, and more.

Consider the difference in the physical impact of walking versus running on the body.

If you walk at a comfortable, leisurely pace for one hour a day every day of the week, the stress on the body will be much less than if you run at 85% of your maximum heart rate for an hour per day.

Although both scenarios result in seven hours of aerobic exercise per week, the running scenario is much more energy-intensive and physically stressful than the walking alternative.

This does not mean that low or moderate-intensity exercise is always preferable to vigorous exercise or that you shouldn’t do any vigorous physical activity. 

However, if you are going to focus on primarily high-intensity or vigorous forms of exercise, the number of minutes of exercise per week you have to do will be less. Furthermore, depending on your fitness level and current health status, you will need to be more mindful about not overdoing it.

So, let’s answer the question, “how many minutes of exercise per week do I need to stay healthy?”

To meet the guidelines for physical activity for adults set forth by the Centers for Disease Control and Prevention and the British Heart Foundation, you should aim to accumulate either 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity cardio exercise per week.1Understanding physical activity. (2020). Bhf.org.uk. https://www.bhf.org.uk/informationsupport/publications/being-active/understanding-physical-activity

There is plenty of research supporting the fact that regularly performing cardio exercise can reduce your risk of certain diseases such as heart disease and stroke, hypertension, obesity, type 2 diabetes, and certain cancers.2Romero, S. A., Minson, C. T., & Halliwill, J. R. (2017). The Cardiovascular System after Exercise. Journal of Applied Physiology122(4), 925–932. https://doi.org/10.1152/japplphysiol.00802.2016

Two people running along the coast.

According to the American College of Sports Medicine, to qualify as a moderate-intensity “cardio” workout, your heart rate should be in the range of 64-76% of your maximum heart rate, while vigorous-intensity cardio is associated with a heart rate of 77-95% of your max.3Scheid, J. L., & O’Donnell, E. (2019). REVISITING HEART RATE TARGET ZONES THROUGH THE LENS OF WEARABLE TECHNOLOGY. ACSMʼs Health & Fitness Journal23(3), 21–26. https://doi.org/10.1249/fit.0000000000000477

This works out to exercising a minimum of 2.5 hours per week if you are working at a moderate intensity and just one hour and 15 minutes per week if you are exercising at a vigorous intensity. 

It’s also important to note that you can do a combination of moderate-intensity and vigorous-intensity exercise each week. This will mean that the number of hours of exercise per week you need to do will be somewhere in the middle of this range.

For example, if you do one 25-minute vigorous workout weekly—running, HIIT (high-intensity interval training), etc.—you’ve done one-third of the vigorous exercise requirements.

This means that you can make up the difference by doing two-thirds of the moderate-intensity requirement, which would be another 100 minutes.

Therefore, you’d need to do 125 minutes of exercise per week or just over two hours of exercise per week.

These are the physical activity minimums required to prevent lifestyle diseases, so keep in mind that you should aim to do more if possible, particularly if your goal is weight loss or improved athletic performance.

A person running up outdoor stairs.

Primary Fitness Goal

As mentioned, if you’re just looking to do enough regular exercise to reduce your risk of disease, you will want to meet the physical activity guidelines set forth by the CDC.

This entails doing 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity cardio exercise per week.

But what if your goal is weight loss? How many hours of exercise a week to lose weight?

If your primary goal is weight loss, you’ll probably want to do more exercise per week than if you’re only trying to satisfy the physical activity minimums for health and disease reduction.

Losing weight requires generating a consistent caloric deficit. This means that you have to burn more calories than you consume.

Although this can be accomplished solely by eating less, adding more physical activity to your routine will help you increase your energy expenditure. The more exercise you do, the more calories you will burn.

A person on a spin bike.

There are no specific guidelines for how much exercise you need to do per week for weight loss. However, according to the Centers for Disease Control and Prevention (CDC), cutting calories and getting at least 30 minutes of exercise daily is the most effective way to manage weight.4U.S. Department of Health and Human Services. (2018). Physical Activity Guidelines for Americans 2nd edition. In health.gov (pp. 1–118). https://health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf

If you do 30 minutes of exercise seven days per week, this equates to 3.5 hours of exercise per week for weight loss.

It’s important to add that although the CDC does recommend creating a caloric deficit to lose weight, a deficit of no more than 3,500-7,000 calories per week—which would yield 1-2 pounds of fat loss—is the suggestion for effective and sustainable weight loss. 

This works out to 500-1000 calories per day. Depending on your body size, diet, and the type and intensity of your workouts, this might entail exercising for more than 30 minutes per day.

Lastly, if your primary goal is improved athletic performance or training for a competition, the number of hours of exercise you need per week will likely be greater.

For example, if you are training for a marathon or the CrossFit Games, you will need to spend more time working out per day to build the fitness you need to succeed in your targeted competition and achieve your desired fitness or health benefits.

A person pressing a button on a treadmill.

Type of Exercise

The type of exercise you do also affects how many hours of exercise you need to do per week.

In terms of aerobic exercise, as discussed, if you are doing types of exercise that are more vigorous, you will not need to do as many minutes of exercise per week as if you opt to mainly do walking or other forms of low-intensity cardio.

Use your heart rate to determine the intensity of your workout regardless of the type of exercise you are doing. 

Depending on your fitness level, a type of exercise that might be considered “low” or “moderate exercise” for some people may actually qualify as vigorous for you.

For example, someone just getting started on a fitness plan might find that incline walking, or even brisk walking on a flat surface, increases your heart rate to 80% of your age-predicted maximum heart rate.

This would qualify as vigorous activity.

Remember, regardless of how you are moving your body, if your heart rate gets up to 64-76% of your maximum heart rate, you are doing moderate-intensity exercise, and if you cross above 77% of your maximum heart rate, you are doing vigorous-intensity cardio.

Cardio Activity Examples

  • Running
  • Cycling/biking
  • Swimming
  • Rowing
A person doing a shoulder press in a gym.

Aside from aerobic activity, your workout routine should include resistance training of some form, whether lifting weights, doing circuit training workouts, or bodyweight exercises.

So when calculating, “how much exercise do I need?” there is just one more component.

The CDC recommends doing a minimum of two total-body strength training workouts per week, targeting all of the major muscle groups in the body. 

These muscle-strengthening training workouts should be above and beyond the 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity exercise.

There aren’t specific guidelines for how long your strength training workouts should be, but getting in two total-body workouts will likely add at least one hour of exercise per week—30 minutes per workout.

Strength Training Examples

  • Weightlifting
  • Bodyweight exercises such as squats, push-ups, pull ups, and more
  • Circuit training workouts

Flexibility exercises such as yoga, tai chi, and dynamic stretching should also be part of your well-rounded exercise routine.

Again, there aren’t specifics for how long these workouts need to last, but aim for 30 minutes per day as a minimum, depending on your fitness goals.

For some ideas for cardio workouts to get started, check out: 7 High-Powered Cardio Workouts At Home That You Can Do Today.

A woman doing a shoulder press with dumbells while looking in the mirror.


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Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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