According to the American Heart Association, only about one in five adults and teens get enough exercise to maintain proper health. That’s a staggering amount of people not getting enough exercise. So how much is enough? What is aerobic activity? Lastly, how many days a week should you work out?
Let’s start with the basic recommendations from the U.S. Department of Health and Human Services.
To start, adding any exercise will always be better than no exercise. Start small. You don’t have to run a marathon next week. Begin by walking each day and work your way up to more intense exercises. This will prevent injury, fatigue, and burnout.
The guidelines from the Department of Health and Human Services are very specific. The HHS recommends 150 minutes per week of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity. You don't have to commit to one or the other. You can combine both types to fit your schedule and fitness level. But be sure to spread it out throughout the week for at least 3 days.
You’ll see even more health benefits after 300 minutes of moderate activity a week. These benefits include lower risk of cardiovascular diseases, gradual weight loss, and improved cognition and quality of sleep.
What is aerobic activity?
Aerobic exercises utilize large muscle groups continuously and consistently. Think running, swimming and cycling. It’s repetitive motions for extended periods of time.
To dig deeper, these large muscle groups use adenosine triphosphate, ATP, as energy. ATP comes from the consumption of carbohydrates, fatty acids, and amino acids.
So how can you measure moderate vs. vigorous aerobic activity? There are a few ways. Let’s start with the easier options.
The first way to test your intensity is the talk test. Can you have a conversation with your workout partner or sing along to your music? If so, you’re exercising at a moderate intensity. If you’re breathy, heavily breathing, and can only get out a few words at a time, your intensity is considered vigorous.
Another option is your perceived effort. As you work out, consider a scale of 1 - 10. How intense are you working? A moderate exercise is about a 3 - 4 on the scale. On the other hand, vigorous exercise is 5 - 7.
The next 2 ways are a little more complicated. They involve wearable tech and calculations.
First up is measuring your heart rate. Heart rate monitors have become wildly popular. These range from chest straps to wrist wearables like watches or bracelets.
To determine your intensity, calculate your maximum heart rate percentage.
First, you'll need to calculate your target heart rate. It’s simple, just subtract your age by 220. For example, if you’re 30 years old, your target heart rate would be 190 beats per minute.
65% to 75% of your maximal heart rate is considered moderate while 76% - 96% is vigorous. To figure out your ranges, multiply the percentage by your target heart rate.
Last up are pedometers or wearable motion sensors to track your steps. A moderate-intensity workout is 100 steps per minute. Vigorous is over 100 steps per minute.
Muscle strengthening activities
In addition to aerobic exercise, the U.S. Department of Health and Human Services also recommends adding moderate to high-intensity muscle-strengthening activity at least 2 days a week. Examples include weight lifting, resistance band workouts, or bodyweight exercises.
What are your goals?
Determining how many days a week you should work out all boils down to your goals. Are you looking to lose weight? Improve your health? Sleep better?
Someone training for a race will exercise more than someone looking to improve their overall health. Above all else, safety always comes first.
Remember, always consult a medical professional before starting any new exercise program.
Understand your current fitness level. You don’t want to start at 75 minutes of vigorous activity if you haven’t exercised in years. Gradually progressing into more intense sessions will lower your chance of injury.
Using the guidelines above, create a workout plan that fits your lifestyle, exercise experience, and current fitness level. Depending on your aerobic workout length and type, you’ll need at least 3 - 5 days per week. Add an additional 2 days for strength training.
Importance of rest days
While you can conceivably work out every day, don’t forget the importance of rest days.
When you exercise, especially weight lifting, you create tiny tears in your muscle fibers. As these microscopic tears heal, they’ll be stronger and more resilient. But you have to give them time to recover.
Rest days will also prevent exercise burnout. If you’re constantly stressing your body without a break, you’re going to lose motivation, not recover from soreness properly, and could start dreading your workouts. If you’re not enjoying the activity, you’re less likely to stick to it.
These less intense days also give you a chance to refuel and replenish your body. Exercising takes a lot of energy and you need time to rebuild your energy stores.
The number of days per week that you work out depends on your goals and schedule. Aim for 150 minutes of moderate activity or 75 minutes of vigorous activity per week. Add at least 2 days of strength training.
This looks different for everyone. You want a sustainable plan. Find the schedule that works for you that includes rest days.
The Department of Health and Human Services recommends 150 minutes per week of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity plus 2 days of muscle strengthening activities.
Aerobic activity uses large muscle groups repetitively for an extended period of time.
There are 4 ways to measure your aerobic intensity ranging from self assessment to wearable technology.
To determine how often you work out, consider your current fitness level, goals and the HHS recommended guidelines.
American Heart Association. American Heart Association Recommendations for Physical Activity in Adults and Kids.
U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans.
National Library of Medicine, National Center for Biotechnology Information. Aerobic vs anaerobic exercise training effects on the cardiovascular system.
American College of Sports Medicine. Tips for Monitoring Aerobic Exercise Intensity.