Cardio is often presented as one of the most important parts of a healthy lifestyle. Whether it’s running, cycling, swimming or spending time on a treadmill, cardiovascular exercise is regularly described as something everyone should be doing. At the same time, you’ve probably heard people say that strength training is more important, leading many beginners to wonder whether cardio is actually necessary at all.
The answer is more balanced than many fitness debates suggest. Cardio offers significant health benefits, but that doesn’t mean you need to become a runner or spend hours exercising every day. Healthy cardiovascular activity comes in many forms, and for most teenagers and young adults, it’s about finding enjoyable ways to move rather than forcing yourself into workouts you dislike.
If you’re comparing different types of exercise, our complete guide to Strength Training vs Cardio: Which Is Better for Beginners? explains how both forms of training contribute to long-term health. This guide looks specifically at cardiovascular exercise, exploring why it’s recommended, what it does for your body and whether you really need it to stay healthy.
What Is Cardio?
Cardio, or cardiovascular exercise, includes any activity that raises your heart rate and breathing for a sustained period of time. As your body works harder, your heart pumps more blood, your lungs deliver more oxygen and your muscles learn to use that oxygen more efficiently.
Walking, cycling, swimming, jogging, dancing, rowing and many team sports all count as cardiovascular exercise. They may look very different from one another, but they all encourage your cardiovascular system to become stronger and more efficient over time.
One of the biggest misconceptions about cardio is that it only means running long distances. In reality, there are many different ways to improve your cardiovascular fitness, and some are much more enjoyable than others depending on your interests.
If you’ve ever wondered whether everyday activities count, our guide to whether walking counts as cardio explains why something as simple as a brisk walk can make a meaningful contribution to your health.
Why Your Heart Needs Exercise Too
When people think about fitness, they often picture stronger muscles or improved appearance. It’s easy to forget that your heart is a muscle as well.
Regular cardiovascular exercise challenges your heart to work more efficiently. Over time, this improves its ability to pump blood around your body, helping deliver oxygen and nutrients wherever they’re needed.
As your cardiovascular fitness develops, everyday activities often begin to feel easier. You may notice you’re less out of breath climbing stairs, walking uphill or playing sport with friends. These improvements aren’t always dramatic, but they make a real difference to your overall quality of life.
Just as strength training develops stronger muscles, cardio develops a stronger cardiovascular system. Both contribute to long-term health in different ways.
Cardio Supports More Than Physical Health
Although cardio is often discussed in terms of heart health, its benefits extend much further than your cardiovascular system.
Regular physical activity can improve energy levels, support better sleep, reduce feelings of stress and help many people feel more positive throughout the day. Exercise also provides opportunities to spend time outdoors, take a break from screens or enjoy activities with friends and family.
For teenagers and young adults in particular, these wider benefits can be just as valuable as the physical improvements. Feeling more energetic, sleeping better and enjoying regular movement often contribute to greater confidence and overall wellbeing.
This is one reason health organisations encourage people to think about exercise as part of a healthy lifestyle rather than simply as a way to change their appearance.
Does Cardio Have to Be Intense?
Absolutely not.
One reason some people avoid cardio is because they imagine exhausting workouts, long-distance runs or high-intensity interval training. While those activities certainly count, they’re far from the only options.
Brisk walking, cycling around your local area, swimming, dancing, hiking or playing football with friends all provide cardiovascular benefits. The best form of cardio is often the one you genuinely enjoy because you’re much more likely to continue doing it consistently.
Building healthy habits is rarely about finding the toughest workout. It’s about finding enjoyable ways to stay active that fit naturally into your everyday life.
Can You Be Healthy Without Doing Traditional Cardio?
This is where the answer becomes a little more nuanced.
If by “cardio” you mean running on a treadmill or completing structured cardio workouts, then no—you don’t necessarily need to do those activities to be healthy.
Many people achieve excellent cardiovascular fitness through sports, hiking, cycling to school or work, swimming, dancing or simply leading an active lifestyle. Even jobs and hobbies that involve regular movement can contribute to your overall activity levels.
What matters isn’t the label attached to the exercise. It’s whether your heart and lungs are regularly challenged through movement.
This is encouraging because it means you don’t have to force yourself into workouts you dislike. If football, tennis, basketball or long walks are what keep you active, those activities still provide valuable cardiovascular benefits.
What Happens If You Never Do Cardio?
If your lifestyle involves very little cardiovascular activity over a long period of time, your cardiovascular fitness may gradually decline.
You might notice yourself becoming out of breath more quickly, feeling tired during everyday activities or finding it harder to keep up during sport and other physical activities.
This doesn’t happen overnight, and everyone’s starting point is different. However, like any part of your fitness, your cardiovascular system responds to how regularly you use it. The less often it’s challenged, the more difficult sustained physical activity can begin to feel.
The good news is that improvements often happen surprisingly quickly once you become more active. Even moderate increases in regular movement can gradually improve your endurance and overall fitness.
Can Strength Training Replace Cardio?
Strength training is one of the best things you can do for your muscles, bones and overall physical health, but it isn’t a complete replacement for cardiovascular exercise.
Resistance training and cardio challenge your body in different ways. While strength training improves muscular strength and supports healthy body composition, cardio specifically develops your heart, lungs and endurance.
Some forms of strength training can certainly increase your heart rate, especially when exercises are performed with minimal rest between sets. However, this isn’t usually the same as the sustained cardiovascular challenge provided by activities such as brisk walking, cycling or swimming.
Rather than viewing one as more important than the other, it’s often more helpful to recognise that each contributes something different to your overall health.
If you’re wondering whether resistance exercise can completely replace cardiovascular training, our guide to whether you can replace cardio with strength training explores the advantages and limitations of both approaches.
How Much Cardio Do You Actually Need?
There isn’t one perfect amount of cardiovascular exercise that suits everyone.
Your age, current fitness level, lifestyle, interests and overall health all influence how much activity is appropriate for you. Some people naturally achieve high activity levels through sport or active hobbies, while others need to make a more conscious effort to include movement in their daily routine.
Rather than worrying about exact numbers, many beginners benefit from asking a simpler question:
Am I moving regularly throughout the week?
If the answer is yes, you’re already building one of the most important habits for long-term health. As your confidence grows, you can gradually increase the variety, duration or intensity of your activities if you wish.
If you’d like more specific guidance, our guide to how much cardio teenagers should do explains current recommendations in a realistic, beginner-friendly way.
Finding Cardio You Actually Enjoy
One of the biggest reasons people stop exercising is because they choose activities they feel they should enjoy instead of activities they genuinely like.
If you dislike running, forcing yourself to run several times every week is unlikely to become a lasting habit. On the other hand, if you enjoy cycling, swimming, dancing, hiking or playing sport with friends, staying active often feels much less like exercise and much more like something you naturally look forward to.
This is one of the reasons long-term fitness isn’t about finding the “best” workout. It’s about discovering forms of movement that fit your personality, your interests and your everyday life.
Healthy habits are almost always easier to maintain when they feel rewarding rather than like another task on your to-do list.
Bringing Everything Together
So, do you need cardio to be healthy?
In most cases, yes—you do need some form of cardiovascular activity. However, that doesn’t mean you need to become a runner, spend hours on a treadmill or complete exhausting workouts every day. Cardio simply means regularly challenging your heart and lungs through movement, and there are countless ways to do that.
Walking, cycling, swimming, dancing, hiking, playing football with friends or taking part in almost any active hobby can all contribute towards improving your cardiovascular fitness. The healthiest form of cardio is often the one you genuinely enjoy because that’s the activity you’re most likely to continue for months and years rather than just a few weeks.
It’s also important to remember that cardio isn’t the only part of a healthy fitness routine. Strength training supports your muscles, bones and posture, while cardiovascular exercise develops your endurance and heart health. Together, they create a balanced foundation for lifelong fitness.
Rather than asking whether you have to do cardio, a more helpful question is whether you’re moving enough to keep your body healthy, strong and capable. For most teenagers and young adults, building regular movement into everyday life is far more valuable than worrying about following the perfect workout programme.