What is the best form of cardio?

Emma White - Certified Personal Trainer | 22 Jun, 2023

In a recent survey, we asked our members what type of exercise they did on a regular basis. Here's how the main cardio activities ranked in terms of popularity (we asked people to tick all that applied):

  • Walking – 61%
  • Running – 24%
  • Swimming – 21%
  • Cycling – 20%

Walking is a clear winner, with over 60% of respondants doing this at least once a week as a form of exercise. Running, swimming and cycling were around the same level of popularity.

So walking, maybe unsurprisingly, is the firm favourite, but what about the overall benefits to health and fitness? Does walking trump all other forms of cardio and justify its popularity? Let's discuss!



Clearly a favourite amongst our members, and for good reason. Walking is something most of us do every day simply to get from A to B. It's hugely accessible, free, doesn't require equipment and is low-impact, meaning it's low risk for causing injury. Thanks to its lower intensity compared to some other forms of cardio, walking is a great starting point for people wanting to get into exercise. It's also a good choice for anyone with joint issues that might be exacerbated by high-impact movements such as running or jumping.

Walking can be as easy or hard as you make it. You can increase your speed or walk on an incline to increase the intensity and boost the calorie burn. To up the fitness boosting benefits, add in some hills and speed walking to get your heart rate elevated!

In terms of calorie burn, a brisk walk on a flat surface can burn around 200 calories per hour (based on a 10st female). Adding a 3% incline to a brisk walk could up the burn to around 230 calories per hour. Or increasing the speed to a very fast walk on a flat surface could up the burn to around 300 calories.

While walking is an accessible and versatile option, it does have limitations. There's only so fast you can walk before you need to break into a run to keep progressing. So while it's a great easy option for remaining active, it does have limited calorie burning potential and fitness gains can only go so far.


  • Low impact
  • Free and easily accessible
  • Can maintain for a long time


  • Not as many fitness benefits as more intense forms of cardio
  • Calorie burn not as high as other forms of cardio



Once you've mastered walking at various different intensities – running would be your next step in terms of progression. Running is undoubtedly a fantastic exercise for improving overall fitness. It's also free and requires just some trainers and a road/path to run on, so it's accessible.

The simple mechanics of running are what make it a much more intense form of exercise than walking. The act of running requires us to propel ourselves forward at a faster rate than if we were walking. What distinguishes a run from a walk is that during running there are moments where neither foot is on the ground as you propel yourself between strides, whereas when walking, one foot is always on the ground. This is why walking is much lower impact – whereas running requires our joints and muscles to handle much more impact when our feet hit the floor with each stride.

The plus points – running raises our heart rate further, improves muscle strength and endurance more, and burns significantly more calories than walking. It's also variable, as you can run at a gentle pace for a longer distance or aim for a faster pace over shorter distances. Hills and sprint intervals can also be added in to boost the intensity of your runs and add variety too.

In terms of calorie expenditure, running at a jogging pace of 6mph can burn around 450 calories per hour (based on a 10st female). Increasing the speed to a faster run of around 8mph however, can up the calorie burn to around 680 calories per hour.

While running is a great form of cardio for burning calories and boosting cardiovascular fitness, it's quite an intense form of exercise that doesn't suit everyone. People who struggle with joint issues or knee problems for example would struggle to run without discomfort and risking injury. It also requires a certain level of fitness, so people will need to work up to it if running is something they've not done before.


  • Great calorie burner
  • Free and easily accessible
  • Fantastic fitness gains


  • High impact which increases the injury risk
  • More challenging so not as popular with some people



Getting out on your bike is not only good exercise, but a great way to explore places and get around. Since you move pretty fast on a bike, you can cover a considerable distance in a short space of time, making it a fantastic active commute option!

Cycling mostly targets the leg muscles, while our core and upper body are used to stabilise us – but as our leg muscles are some of the biggest in our body, it's still a decent calorie burner. The action of pushing the pedals round and round activates the legs, which in turn raises our heart rate and breathing as our body needs more oxygen to support the working muscles. This makes it a great cardiovascular exercise.

Cycling is also modifiable as you can pick a higher gear and go for a leisurely cycle, or lower gear to up the resistance and work your leg muscles harder. Also, hill climbing on a bike is great for building up the muscles of the legs and bum. The option to add heavy resistance to the pedals of a bike makes it a good choice if you're wanting to tone up your legs, as you will build more muscle working against a resistance.

It's also a low-impact option due to the fact you're seated and your legs are working in a circular motion, rather than up and down and impacting the floor. This makes it a good choice for anyone struggling with joint or knee issues.

In terms of calorie burn, a gentle cycle of around 10-12mph can burn around 300 calories per hour (based on a 10st female). Increase this to a more vigorous cycle of 14-16mph and you could burn closer to 570 calories per hour.

While cycling is a great low impact choice for cardio, you obviously need a bike in order to take part – or a gym membership to use an indoor bike, so it may not be as accessible if someone can't afford these things. It's great for overall cardiovascular heath and building up leg muscles, but due to the seated position and smaller involvement from the upper body, it's not quite as big a calorie burner as running when measured on intensity.


  • Low impact
  • Great commute option
  • Versatile


  • Needs equipment
  • Not quite as high a calorie burner as running



Swimming is a great full body workout as most strokes require all of your body to be moving. Working against the resistance of the water and using your muscles to keep yourself afloat makes it a great cardiovascular exercise.

It helps to build and tone muscles, especially around the upper body (we've all seen the classic swimmers V-frame body shape!). As well as being great for cardiovascular fitness, as our heart and lungs work hard to support the full body movement.

Swimming can be carried out at a leisurely pace, making it a good option for people who don't like to do anything too intense, or which causes huge amounts of sweating. It's also very low impact since you're floating in water, so it's a really good choice for anyone with injuries or joint pain.

In terms of calorie burn, a leisurely swim can burn around 300 calories per hour (based on a 10st female). Or upping the intensity and opting for a front crawl with vigorous effort, could burn around 600 calories per hour. This requires quite a pace though, which takes some practice!

Swimming is a great, low-impact choice for cardio exercise – but the downside is you need a swimming pool to do it. So it's not as accessible as walking or running, as you need to pay to use a pool (unless you're lucky enough to have your own!). As the water supports your muscles and reduces any impact, it's not as taxing as running, so it does require more effort to burn as many calories as running.


  • Low impact
  • Full body workout
  • Versatile


  • Not as accessible
  • Lower impact so not as good a calorie burner as running
  • Not always convenient as requires a trip to the pool

Which one wins?

As you can see, each of the cardio exercises discussed come with their own pros and cons. All are fantastic choices for keeping fit and active and will benefit your overall health. Ultimately it comes down to finding something you can access and that you enjoy. You're far more likely to continue doing something if you enjoy doing it – and consistency is key when it comes to exercise. Progression is also important, so when you find that thing you love, keep increasing the intensity or duration so you keep reaping the benefits!

Emma White (Certified Personal Trainer) has always loved fitness. She's passionate about the many benefits of regular exercise, particularly the positive impact on mental health and overall quality of life, as well as how it provides the key to successful weight management.

This site uses cookies to personalise content and ads, provide social media features and analyse our traffic. Find out more about how we use cookies.

Choose which cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy.