Walking, swimming and HIIT can all improve cardiovascular fitness, but which one is best for you? A cardiologist explains the benefits of each cardio workout and how to choose the right one
When people hear the word cardio, running is often the first exercise that comes to mind. But you do not have to run to improve cardiovascular fitness.
Walking, swimming and high-intensity interval training (HIIT) can all provide an effective cardiovascular workout, with each offering different benefits.
According to Dr Deepak Krishnamurthy, Director & Lead Consultant, Cardiology, KIMS Hospitals, Mahadevapura, Bengaluru, the best form of cardio is not necessarily the most intense one.
“The most effective cardio exercise is the one that you can perform safely, consistently and enjoy doing,” says Dr Krishnamurthy. “Running is an excellent cardiovascular exercise, but it is certainly not the only option. Walking, swimming and HIIT can all improve cardiovascular fitness when incorporated appropriately into a regular exercise routine.”
Walking: Easy, effective and gentle on the joints
For someone who has been inactive for a long time, brisk walking can be one of the easiest ways to introduce cardio into a daily routine.
“Walking is often underestimated because it is simple, but regular brisk walking can significantly improve cardiovascular fitness,” says Dr Krishnamurthy. “It is particularly useful for older adults, beginners and people returning to exercise after a long break.”
Walking is also a relatively low-impact activity, placing less stress on the joints than running. The intensity can be increased gradually by increasing the pace, walking uphill or extending the duration.
More from Lifestyle
Benefits of walking
Regular brisk walking can improve cardiovascular fitness, help burn calories and support weight management, improve blood sugar control, support blood pressure management, strengthen the muscles of the legs, improve endurance, and provide a relatively joint-friendly way to stay active.
“Starting with a manageable duration and gradually increasing the pace and distance is more important than trying to walk extremely fast from day one,” Dr Krishnamurthy adds.
Swimming: A full-body cardio workout
Swimming offers a different kind of cardiovascular challenge because the body has to move against the resistance of water. At the same time, the buoyancy of water reduces the impact on the joints.
“Swimming is an excellent option for people looking for a low-impact cardiovascular workout,” says Dr Krishnamurthy. “It engages several major muscle groups while the resistance of the water makes the body work continuously.”
This can make swimming particularly appealing to people who find high-impact activities uncomfortable or want to add variety to their exercise routine.
However, access to a pool and basic swimming ability are important. Beginners who are not confident in the water should first learn proper swimming techniques rather than treating swimming as an exercise they can immediately undertake at high intensity.
Benefits of swimming
Swimming can improve cardiovascular endurance, work multiple muscle groups simultaneously, build muscular endurance, burn calories, improve overall stamina, provide a low-impact workout, and reduce stress on weight-bearing joints.
“Because swimming combines cardiovascular activity with muscular involvement, it can be a very efficient workout,” Dr Krishnamurthy says. “However, the intensity should be appropriate to the person’s fitness level.”
HIIT: Short but intense
For people with limited time, high-intensity interval training, commonly known as HIIT, can offer a time-efficient approach to cardio.
HIIT involves alternating short periods of vigorous exercise with periods of rest or lower-intensity activity. A session can include activities such as fast cycling, running, bodyweight exercises or other movements, depending on the individual’s fitness level.
“HIIT can provide a strong cardiovascular stimulus in a relatively short period,” says Dr Krishnamurthy. “But because the intensity is high, it is not automatically suitable for everyone.”
Beginners should avoid jumping straight into extremely demanding HIIT sessions. People with underlying health conditions should also seek appropriate medical and exercise guidance before starting vigorous training.
Benefits of HIIT
When appropriately performed, HIIT can improve cardiovascular fitness, increase exercise intensity in a shorter workout, improve endurance, help burn calories, add variety to an exercise routine, challenge both cardiovascular and muscular systems, and be useful for people who struggle to find time for longer workouts.
“The key with HIIT is not simply to exercise as hard as possible,” Dr Krishnamurthy explains. “The intervals, recovery periods and exercise intensity should be adjusted according to the person’s fitness and health status.”
So, which cardio exercise is the best?
There is no universal winner when it comes to cardio. Walking, swimming and HIIT serve different needs, and the right choice depends on a person’s fitness level, health, preferences, available time and ability to exercise safely.
“Someone who wants a simple form of daily cardio may benefit greatly from brisk walking,” says Dr Krishnamurthy. “Swimming may be preferable for someone looking for a low-impact, full-body workout, while HIIT can suit people who are already conditioned and want a more intense, time-efficient session.”
Consistency matters more than choosing the perfect workout
One of the biggest mistakes people make is focusing too much on finding the single “best” exercise and too little on doing it regularly.
“The benefits of cardio come from consistency,” Dr Krishnamurthy says. “There is little advantage in doing an extremely difficult workout once in a while if you are unable to maintain it.”
Mixing different forms of cardio can also make exercise more enjoyable. Someone might walk on most days, swim once or twice a week and incorporate occasional higher-intensity sessions, depending on their fitness and medical circumstances.
Choose cardio you can sustain
Running remains an excellent cardiovascular exercise, but it is far from the only option. Brisk walking can provide an accessible starting point, swimming can deliver a low-impact full-body workout, and HIIT can offer an intense session when time is limited.
Ultimately, the best cardio exercise is the one that matches your abilities and that you can perform safely and consistently.
“Rather than asking whether walking, swimming or HIIT is universally better, ask which activity you can do regularly and safely,” Dr Krishnamurthy says. “That is what makes an exercise routine sustainable and, ultimately, beneficial for heart health.”