Can swimming replace running?

[Kirsten]

Instead of running on Tues./Thurs. I have been swimming 1 1/2 to 2 miles each time.  Should I still be running on those days? Are there any benefits swimming brings to my running at all other than that it's non impact? (Sorry if this question has already been asked) 

[Sasha Pachev]

Swimming and running are sufficiently unrelated sports that they do not aide each other very much. You would think the cardio benefits would carry over, but it turns out that cardio is a very small, almost insignificant component of endurance. Most of it is in the muscle itself and in the way the brain knows how to use the muscle. Cardio just has to be there to support the activity, and unless you have some pathology is usually sufficient to support the maximum efforts that the muscles are capable of. The limit usually comes from the muscle and the brain, not the heart.

If your goal is to be a good runner, you should spend as much time and energy as you have available on running.

[Paul Petersen]

I pretty much agree with Sasha, but will add that if you enjoy swimming, then it's great to swim a few days/week. Or if swimming helps you stay healthy (uninjured), then it is a worthwhile activity. But other than the aesthetic and injury-prevention values, I don't see much use in cross training, as the best way to get good at running is to run a lot.

[Joe]

I can vouch from the swimmer side - I swam competitively my entire childhood until I was 19, was pretty good at it, and was always a slowpoke runner.  I could always sprint (run) well but had horrible running endurance even though I'd swim 3-4 miles a day.

[Davy Crockett]

When I got injured last year, I used swimming to keep my endurance up.   It worked fine.  But I was swimming 2-5 miles.   I then quickly got back in the saddle once I recovered and didn't seem to have lost very much at all, PRed at marthon distance without much running training that month.

[CSP4960]

I disagree with the statements on swimming to a degree.  On days that you are not running by cross training (swimming, biking, rowing, etc) will help you continue build fitness.  A consistent program of running 3-4 days a week with cross training in between builds and helps you maintain your fitness levels.  Example: During times of running injuries increasing meters in the pool has been a source of maintaining fitness and making it easier to come back to running.  If all you do is swim 5-6 days a week you will be continually gain fitness but in a different capacity. 

[Davy Crockett]

I agree.  Another thing that worked for me.  Before I was in good running shape, and when I was overweight, I used swimming as cross-training because my legs just couldn't handle running every day.  The swimming really helped shed the pounds.   I used to be 50 pounds heavier.

[Jeff Linger]

This returns to the age-old question: Minimized specificity training v. maximized specificity training v. cross training. A few things. 1. Maximized specificity training (running 6 days a week) will always make you a better runner (once your body is prepared to handle the volume) than cross-training (running 4 days and CT 2). Cross-training however will provide more benefits than minimized specificity training (running only 3-4 days/week). The optimal training would be CT in addition to 6 days/week. Injuries are of course a different matter. But you cannot replace running with something else and ever think that doing that something else will make you a better runner. Having said that, runners frequently overlook the benefits of CT. Running only, overdeveloping the running muscles and neglecting other muscles, will lead to problems later. Additionally, improvement of back muscles, core muscles, etc will allow you to possess better running form and enhance running economy, in turn making you a better runner.