If you’ve spent any time looking for fitness advice online, you’ve probably seen people arguing that you should either lift weights or do cardio.
Some people claim strength training is the only exercise that matters. Others suggest cardio is the key to getting fit and losing body fat.
The truth is much simpler.
For most teenagers and young adults, strength training and cardio aren’t competing forms of exercise. They’re complementary.
Each develops your body in different ways, and together they create a healthier, more balanced fitness routine than either could achieve on its own.
This article is part of our Fat Loss & Cardio for Beginners (Healthy & Sustainable) cluster, where we explain how different types of exercise contribute to healthy body composition. If you’re wondering whether you have to choose between lifting weights and cardio, the answer is almost certainly no.
You may also find Can You Build Muscle and Do Cardio at the Same Time? helpful, as it explains why combining both forms of exercise doesn’t usually stop you building muscle.
Do You Really Need Both?
In most cases, yes.
Strength training and cardio improve different aspects of your health and fitness.
Strength training makes your muscles stronger, supports healthy bones and helps improve your body composition.
Cardio strengthens your heart and lungs, improves endurance and helps you stay active for longer without becoming tired.
If you only focus on one type of exercise, you’re likely to miss out on many of the benefits the other can provide.
Think of them as two pieces of the same puzzle.
Together, they help you build a body that’s not only stronger but also fitter, healthier and better prepared for everyday life.
What Strength Training Does for Your Body
Strength training places your muscles under resistance, encouraging them to adapt over time.
As you continue training consistently, your muscles become stronger and more capable of handling everyday tasks as well as sporting activities.
Strength training can also improve posture, balance and coordination while supporting healthy bone development during adolescence and early adulthood.
For many people, it also increases confidence as they notice themselves becoming stronger and more capable over time.
If your goal is improving body composition, resistance training helps preserve and build lean muscle, which plays an important role in long-term health.
However, strength training isn’t just about lifting the heaviest weights possible.
Bodyweight exercises, resistance bands, kettlebells, dumbbells and machines can all help you become stronger when used consistently with good technique.
What Cardio Does for Your Body
Cardiovascular exercise challenges a different system.
Instead of primarily targeting your muscles, cardio improves how efficiently your heart, lungs and circulatory system work together.
Over time, regular cardio can help you exercise for longer before becoming tired, recover more quickly after physical activity and improve your overall stamina.
Cardio also supports many aspects of long-term health, including maintaining a healthy heart and encouraging an active lifestyle.
Importantly, cardio doesn’t only mean running.
Walking, cycling, swimming, rowing, dancing, hiking and playing sports all count as cardiovascular exercise.
If you’re unsure which activities suit you best, our guide What Is the Best Type of Cardio for Beginners? explores several beginner-friendly options.
Why Choosing Only One Can Limit Your Progress
Imagine someone who only lifts weights but never does any cardio.
They may become significantly stronger, yet still find themselves out of breath after climbing several flights of stairs or playing an energetic game with friends.
Now imagine someone who only does cardio.
They may have excellent endurance but miss many of the benefits that come from building strength, such as increased muscle mass, stronger bones and improved physical resilience.
Neither approach is necessarily “wrong.”
But for most teenagers and young adults who simply want to become healthier, fitter and more confident, combining both forms of exercise creates a far more balanced outcome.
How Strength Training and Cardio Work Together
Rather than competing with one another, strength training and cardio each improve different parts of your fitness.
Strength training develops muscular strength, power and stability.
Cardio develops endurance and the efficiency of your heart and lungs.
When you combine the two, your body becomes better equipped to handle everything from playing sports and climbing hills to carrying shopping or spending an active day outdoors.
This is why many coaches encourage balanced training programmes instead of focusing exclusively on one style of exercise.
You’re developing a body that’s capable in many different ways, rather than becoming highly specialised in just one area.
Together They Support Healthier Body Composition
Many people begin exercising because they want to lose body fat, gain muscle or feel more confident in their appearance.
Strength training and cardio can both contribute to these goals, but they do so in different ways.
Strength training provides the stimulus your muscles need to become stronger and, over time, increase in size.
Cardio increases your overall physical activity while improving your cardiovascular fitness.
When these are combined with balanced nutrition and good recovery, they can support healthy improvements in body composition.
Instead of thinking only about losing weight, it can be more helpful to focus on becoming stronger, fitter and healthier overall.
Our article Does Cardio Help You Lose Body Fat? explains why body fat loss is influenced by your overall lifestyle rather than a single type of exercise.
Cardio Can Even Support Your Strength Training
Many people think cardio will automatically make their strength workouts worse.
In reality, improving your cardiovascular fitness can actually make resistance training feel easier.
As your endurance improves, you may find that you recover more comfortably between sets, feel less breathless during demanding workouts and maintain better energy levels throughout your training session.
This doesn’t mean you should perform long, exhausting cardio sessions before every strength workout.
Instead, maintaining a sensible level of cardiovascular fitness can help support your overall training capacity.
If you’re unsure how to combine both types of exercise, Should You Do Cardio Before or After Weights? explains how workout order can be adapted depending on your goals.
Strength Training Supports Everyday Movement Too
Although lifting weights is often associated with building muscle, its benefits extend far beyond appearance.
Greater strength can make everyday activities feel easier.
Carrying heavy bags, moving furniture, climbing stairs or taking part in recreational sports all become less physically demanding as your strength improves.
Building stronger muscles can also improve balance, posture and joint stability, helping you move with greater confidence.
When these benefits are combined with the improved endurance that comes from cardio, many people notice that everyday life simply feels easier.
Both Forms of Exercise Support Your Mental Wellbeing
Exercise isn’t only about physical health.
Many teenagers and young adults find that being active also helps them manage stress, improve their mood and feel more confident.
Strength training often provides a sense of achievement as you gradually become stronger and reach new milestones.
Cardio can offer similar benefits, whether that’s enjoying a peaceful walk, clearing your mind during a run or having fun playing sport with friends.
Choosing activities you genuinely enjoy makes it much easier to build habits that last.
Rather than forcing yourself into a workout you dislike because someone online says it’s “best,” focus on finding a combination of strength training and cardio that fits your interests and lifestyle.
It’s Not About Being Perfect
One of the biggest mistakes beginners make is believing they need the perfect programme before they can make progress.
In reality, consistency has a much greater impact than endlessly adjusting your workout plan.
Two strength-training sessions and two enjoyable cardio sessions each week, performed consistently for months, will almost always produce better results than an ambitious routine that’s abandoned after a fortnight.
The goal isn’t to create the perfect training schedule.
It’s to build healthy habits that become a natural part of your everyday life.
How to Build a Balanced Weekly Routine
You don’t need to spend hours exercising every day to benefit from both strength training and cardio.
For most teenagers and young adults, a simple, balanced routine is enough to build strength, improve fitness and support long-term health.
A typical week might include two or three strength-training sessions alongside two or three cardio sessions.
Those cardio sessions could involve walking, cycling, swimming, running or playing a sport you enjoy.
Your strength workouts might focus on full-body exercises using bodyweight movements, resistance bands, dumbbells or gym equipment.
The exact routine matters less than whether you can follow it consistently.
If you’re new to exercise, starting small is often the best approach. You can gradually increase the amount of training as your confidence and fitness improve.
You Don’t Have to Love the Gym to Be Fit
One of the biggest misconceptions about fitness is that everyone needs to spend hours lifting weights in a gym.
In reality, strength training can take many different forms.
Bodyweight exercises such as squats, lunges, push-ups and planks can all help build strength.
Resistance bands provide an inexpensive way to train at home, while free weights and machines offer additional options if you enjoy going to a gym.
The same is true for cardio.
You don’t have to become a runner if running isn’t something you enjoy.
Walking with friends, swimming, cycling, hiking, dancing or playing football all improve your cardiovascular fitness.
Finding activities that genuinely interest you makes it much more likely that you’ll stay active over the long term.
Common Mistakes to Avoid
Thinking You Have to Pick One
Perhaps the biggest mistake is believing that cardio and strength training are somehow competing against each other.
As we’ve explored throughout this article, they develop different aspects of your fitness and often work best when combined.
Doing Too Much Too Soon
It’s easy to become enthusiastic when starting a new fitness routine.
However, trying to fit in daily strength workouts alongside intense cardio sessions can quickly lead to fatigue and frustration.
Building your routine gradually gives your body time to adapt while making your new habits easier to maintain.
Ignoring Recovery
Exercise is only one part of becoming fitter.
Your body also needs enough sleep, nutritious food and recovery time between demanding sessions.
Giving yourself permission to rest isn’t laziness—it’s an important part of improving your fitness.
Comparing Yourself to Influencers
Social media often shows carefully edited highlights rather than everyday reality.
The routines followed by professional athletes or fitness influencers may not be appropriate for someone who’s just beginning.
Focus on your own progress instead of comparing yourself with people whose goals, experience and circumstances may be completely different.
Building Habits That Last
The healthiest fitness routines aren’t usually the most complicated.
They’re the ones that fit comfortably into everyday life.
If you enjoy your workouts, feel yourself becoming stronger and gradually notice improvements in your fitness, you’re far more likely to continue exercising over the months and years ahead.
That long-term consistency is where many of the biggest health benefits come from.
Rather than trying to create the perfect training programme, focus on building a routine that’s realistic, enjoyable and flexible enough to adapt as your life changes.
Final Thoughts
Strength training and cardio aren’t rivals.
They each develop different qualities that contribute to your overall health and fitness.
Strength training helps you become stronger, supports healthy bones and improves body composition. Cardio strengthens your heart and lungs, improves endurance and helps you stay active throughout everyday life.
When you combine them with balanced nutrition, good recovery and realistic expectations, they create a foundation for lifelong health rather than short-term results.
Instead of asking which type of exercise is “better,” ask yourself which combination of activities you’ll genuinely enjoy and be able to continue doing consistently. That’s usually where the greatest progress begins.