Swimming vs. Running: A Breakdown

Photo Courtesy: David Mielke

There is a certain camaraderie between swimmers and runners. It’s indescribable, but the two cardio-intensive sports often are paired. Many swimmers try to cross-train into running and vice-versa, but find it difficult to adapt to the different mechanics that the other sport demands. The likes of Florent Manaudou are among those for whom running is a non-starter, for example.

The Natural vs the Unnatural:

Dr. Howard Wainer of Princeton released a study to the American Statistical Association’s journal Chance in 1993 detailing the statistical differences between swimming and running. Dr. Wainer realized that humans were not built to be able to effectively travel through water at the same speeds as on land. He found that within the same timeframe, runners, on average, travel three and half times the distance that swimmers do.

Running is a natural motion for the human body. Humans have needed the ability to run for centuries and have evolved to be able to run more effectively for longer distances. Swimming, in comparison, is much more modern. The ability to swim has never been needed for humans to continue to survive so the human body has not adapted into a more swimmer-friendly shape. Because of this lack of adaption, swimmers face more drag while in the water than runners do.


Studies by NutriStrategy have shown that running and swimming are comparable in the amount of calories spent. Swimming the freestyle stroke for 30 minutes burns just about as many calories as running on a treadmill at six and a half miles per hour for thirty minutes.


Though similar in caloric expenditure, the mechanics of swimming and running are vastly different.  The two exercises have some overlap in the muscle groups used, though swimming utilizes many more than running.

Running: There are five main muscle groups used while running, mostly focused in the runners’ legs. The quadriceps, the calves, the core, the glutes, and the hamstrings are all essential muscles that runners must train to reach their peak performance.

Swimming: Swimming is much more of a full-body exercise. Swimmers train 24 separate voluntary muscles to reach their peak performance. Muscles from the sternocleidomastoid in the neck to the flexor digitorum brevis in the foot are used in the freestyle stroke. Swimmers’ entire bodies are utilized when swimming, so during training and conditioning, swimmers must focus on working all 24 of these muscles.

The difference in impact felt while performing these two activities is important as well. Running can do damage to joints. The impact of consistently pushing off the ground can damage the cartilage in the knees. While there are methods of mitigating some damage, running will always require force from the runners’ legs pushing off against resistance. This is why runners are more prone to injuries like shin splints. Swimmers feel little to no impact while exercising. Apart from the wall turn, swimmers have no contact with anything but the water. This is healthier for joint health in the long run and is why many athletes with arthritis or bad joints choose swimming over running.


Both running and swimming depend on strong lung strength to oxygenate the muscles while the actions are being performed. Regulating breathing while running is important, but not vital to the success of the runner. However, for swimmers, breathing can take seconds away from their final times. Swimmers train their breathing to be quick, short, and spaced out. Swimmers, therefore, receive less oxygen while exercising, and is the reason many people feel more exhausted after swimming for 30 minutes as compared to running for 30 minutes.

These two breathing techniques are also why it’s hard for swimmers to run. Adapting to the slower, consistent breaths feels unnatural for many swimmers.

All commentaries are the opinion of the author and do not necessarily reflect the views of Swimming World Magazine nor its staff. All swimming and dryland training and instruction should be performed under the supervision of a qualified coach or instructor, and in circumstances that ensure the safety of participants.


  1. avatar
    Paul Bennett Walker

    I’m a swimmer and runner and love the duathlon. I love the feeling of going from the pool to the track and often wonder if the sports compliment each other. One big difference between the two is the length of the Achilles — swimmers have short Achilles from kicking with their toes pointed, and runners tend to have longer and more flexible Achilles. That’s mostly a challenge for swimmers who have a hard time running unless they train properly, such as starting slow and building up strength and flexibility. In any case, I found your article interesting.

  2. Tomas Yksvoik

    Thanks to this article, now I finaly know why I am so tired after swimming

  3. avatar
    Andrade A.

    Great article!

    • Sandra Lucas

      Great article thanks for the tag

  4. Andrew Liam LaBonne

    “Running is a natural motion for the human body. Humans have needed the ability to run for centuries” imma go out on a limb at say millennia

    • Neal Durbin

      Lol. That is literally what we are built for, and how we acquired food before we developed weapons.

  5. Kok Mei Hui

    funny, i never feel tired after running or swimming ..

  6. Sari Puzio Carroll

    I coach an age group swim team and we have just discovered that swimmers kill it on the track. One of my swimmers joined freshman track and has never ran in his life. His first time competing in the mile he went 5:04. As the season progressed, he started making more track practices and less swim ones, he then got slower at running.

  7. Alan Godfrey

    “Comradery “????!! Is this a new word ?

    • Banjamin Gro

      Damn yanks butchering the English language again! ?

  8. avatar

    Due to a back injury, I had to get in the pool. Runner turning swimmer. To begin with lung capacity was a killer. But after my swimming endurance built up and I learned to breathe through diaphragm while swimming, I found when I got back in the trails to run…running is so much easier. Swimming taught me to regulate my breathing. I still can’t run as much as I used to, but due to the therapeutic tendencies of swimming I can still run a few days a week. It strengthens your back, core, hips, and lungs. If I don’t swim, I can’t run. Go figure. One compliments the other.

  9. Paul Anthony

    I swim and run. Both are tough sports but swimming is harder. More muscles needed and breathing restriction in swimming. Environment more controlled in pool swimming, but it’s still way harder.

  10. Jo Hill

    Caroline Mcgurk noooooo running..🤮

    • Caroline Mcgurk

      Jo Hill nooooo running only swimming 🏊🏾‍♀️

    • Jo Hill

      Fast walking is ok

    • Jo Hill

      And slow walking 😊

  11. Barbara Capellini

    I do not agree with the natural vs unnatural comment. Swimming feels more natural than running to me. I am too uncoordinated and feel “heavy” on dryland. It is logical it takes more time to swim the same distance as you would run, due to resistance of the water (not just a matter of “ability”).

  12. Lisa Wills

    Mitchell Wills Benjamin Wills

  13. Ebony Story

    Becca Woods our age old argument

  14. Daniel Pusztai

    Tori Lawrence the breathing thing is so true

    • Brian Keane

      Laura McNulty Really interesting and makes a lot of sense.I find a 30 min swim much easier though.

  15. Carly Barnett

    Rachel Nicholls Was MeredithGary Barnett

  16. Henry Hu

    Danielle Fang scientific evidence for the effectiveness of a swim-track mixer!

    • Danielle Fang

      Henry Hu Sarah Ishamuddin Emily Niu Katie Williams Liana Reilly

  17. Mike Heath

    Ruby Heath – Swimming Molly Heath

  18. Regan Leong

    Thats weird? Swimmers have more drag in the water than runners?

    Umm ok….?

  19. Jennifer Buckley

    So I ran 3 days after the pool closed….torn meniscus