Which is better exercise - swimming or running?

Since we're on the subject of swimming (MrsBabySalute's menion of swimming), I was wondering what's a better exercise - swimming or running?

I read somewhere that swimming is good if you work hard, but not so great if you just float around.

Also how far should you swim to get a "good" workout? I swam about 500 meters the other day and I was pooped! I guess it takes time to build up endurance? :)

I'm not a doctor, but I'd assume swimming would be better as far as wear-and-tear on your joints. I'd tone up really well with running, but my knees are paying for it now! I'd swim, but that's just me.

Good luck!

Apparently, swimming is considered the best exercise because you are using every single part of your body - your heart, your lungs, your arms, you legs... Running really takes a toll on your knees and joints, just like MarisaOC said.

It's different for everyone as far as a "good" workout goes. Every time I go to the pool, I swim about 1,800 meters in 45 minutes. That's about one mile... and I do that 3 times a week. You just have to build up your endurance. 500 meters is a good start, but as long as you swim at least 30 minutes non-stop, you are getting a "pretty good" workout.

I lost 10+ pounds in the last couple of months from improved diet and increased activity. I think it really depends on how much you enjoy either running or swimming. True, swimming is much easier on the knees and that is a plus, but if you don't enjoy swimming and it is dreadful, then run if your joints can handle it. We are all pretty young here so unless you've had some traumatic injury in the past, I think our knees should be pretty good. Because of timing issues, lately I've been running 2-4 miles/3 times per week. I like to alternate between swimming and running. Also, lifting weights is excellent on the cardio off days. I just bought some free weights and do them at home to save time. In terms of how far or long one should do cardio, I think a solid 40-60 minutes a day is great. You will progressively build up your endurance. If your schedule can't handle it, then any amount is good to just get the heart pumping.

Your body needs impact exercises from time to time, to keep the joints, tendons and connective tissue in good shape. If you can choose between swimming and running, the best would be to run a few times a week and swim the rest. I think swimming is better at getting toned.

If losing weight is the biggest concern, you need to increase metabolism. Weightlifting allows you to build muscle, which burns more calories while you're not exercising.

You were asking about endurance - it's not as important as being consistent; the endurance will come naturally.

I know both superfit runners and swimmers. I think working hard consistently is the biggest factor for fitness and that the particular activity is secondary.

For endurance... Again, I think consistency is the biggest factor. I'll add though that I know that I can be going to the gym a lot, but still not be in the best shape for running. I think some activities, including both running and swimming, are very targeted to specific muscle groups. So while general cardio and weight training always help endurance, if you haven't swam lately, your endurance for swimming might need a few sessions to increase. :)

I am a marathoner (ran 21 marathons in the last 5 years) so personally, I'd have to say running. To get the same fitness benefit from swimming as you get from running, you'd have to go at it for a lot longer. But of course running doesn't tone the arms or shoulders as swimming does...depends on what you are looking for and what you enjoy doing.

I have Scoliosis so I always opt for low impact cardio. Each person is different. Honestly, in my experience alternating various forms of cardio with some resistance training gives me the best results. Your body can develop what's called muscle memory, so its good to change up your work out regardless of what you do (ie. cycling, running, swimming, etc.). Another option to running is using an Eliptical machine. Its the same type of cardio routine as running with out the impact on your body.