Hacker News Reader

Comment by 13ren | Hacker News Reader

This story is making the rounds, but as presented, it doesn't distinguish cause and correlation. Maybe the people who enjoy running are the ones who were fit in the first place? eg. if you have bad joints and a bad heart, you probably won't enjoy running much. Therefore, runners are healthier...

Of course, the causation theory is very appealing, and I personally find I feel much better, and have greater intelligence, when I exercise aerobically. I definitely intend to keep at it... and suggest you do too. :-)

EDIT from page 2: "People who took up exercise when they were older also improved their health" - that suggests causation, but it also depends on who took up the exercise. Perhaps the people who responded well to it.

View on HN

My current understanding is that running is way better than no exercise, but that other forms of exercise are quite likely better for your long-term health because of the impact stress running puts on your knees, feet, etc.

One of the best forms of exercise is swimming. Near zero-impact on joints. For those of you who think they can't learn how to swim, check out Total Immersion's zen-like, go with the water method. (http://www.totalimmersion.net). I learned how to swim freestyle through their video. Most swimming courses emphasize using your arms like paddle wheels to plow through the water, while TI emphasizes swimming much like fish and advanced swimmers do, by propelling from the core. TI is harder to learn but more efficient once you learn by progressing through their balance and core propulsion drills.

Swimming also puts you in better shape IMO. I used to run plenty, but my knees started hurting, so now I only run if I am actually playing a sport. I took up swimming for my exercise. I'd never taken a swimming lesson in my life, but I just went to the pool and started doing it. A few times I asked the life guards for some tips, and I also chatted up some of the good swimmers and got tips from them.

I went for a 2k run the other day just to see what it was like after swimming but not running for a couple months. It was about the same as when I ran everyday (maybe even a bit easier), and I have a slightly more toned upper body now.

You mean you did not know how to swim before? Or that you did not know how to swim efficently?

I didn't know how to swim efficiently: if you threw me in the pool, I wouldn't drown, and I could maybe do one continuous lap (50m) if I pushed myself.

+1 for the TotalImmersion link. I swim about 10K a week at a reasonable, but not superstar pace, and the TI drills improved my stroke no end a few years back. I can now swim a length of a 25 meter pool in 16 - 18 strokes, where as most of 'paddle wheelers' notch up about 25 - 30 strokes per length and hence tire much more quickly.

Here is a potential conundrum that I have never quite understood:

If your goal is to get a workout (burn calories, raise your heart rate, move your muscles, etc.), then why would you want to learn to swim more efficiently? Wouldn't it just take more time to achieve the same amount of exertion?

Of course I understand that if you want to win a race you need to be efficient, but it seems to run counter to the goal of exercising. No?

it wouldn't really take more time because you can still get your heart rate up quickly while swimming correctly.

Swimming efficiently also is more of a full body workout I think than just paddling your arms.

Also swimming poorly can be frustrating and would make people not want to work out as long or maybe give up swimming alltogether.

If around 98% of your energy can be lost due to water resistance, small improvements in efficiency are key. TI was the difference between not literally being able to swim 50m straight (near hyperventilating like I ran a 100m dash) and 1 mile swims (albeit slow). As for why I posted about TI, it fits in the hacker ethos - doing something differently but better.

http://en.wikipedia.org/wiki/Anaerobic Some beginner swimmers (including myself before TI) swim anaerobically (lactic acid produced, pain in muscles). Only with better technique will you be able to swim aerobically (laps).

"Olympic swimmers are able, at best, to convert only 9 percent of their energy into forward movement while swimming the front crawl or freestyle, the fastest and most efficient of the four competitive strokes. (On average, the butterfly, backstroke and breaststroke follow in speed and efficiency.) Most of the rest of us use as much as 98 percent of our energy overcoming water resistance. " (2)

"But the real killer for competitive swimmers is a third type of resistance that arises at the interface between air and water—wave drag. Moving along the surface of the water inevitably creates waves. Physically speaking, swimmers force a mass of water in front of them to rise up against gravity. This not only robs swimmers of energy, but it has a disproportionately greater effect the faster they go.

The problem is that wave drag increases as the cube of any increase in swimming speed. And it gets worse if a swimmer makes jerky or uneven movements, either bouncing in the water or moving from side to side, because this wastes still more energy making waves." (1)

(1) http://environment.newscientist.com/article/mg15921455.600-s...

(2) http://gymkhana.iitb.ac.in/~swimclub/swim4.html

It's similar to the argument of riding on half-flat tires, because it gives you a better workout.

But it feels fantastic to move efficiently. I don't know if that gives a better physical benefit (though I bet it's a factor) but it provides motivation. And that helps with the most crucial factor of all for effective exercise: to do it.

Well as I got better at swimming, I upped my distance too ... so I cover more distance by going faster and its more enjoyable too. It also upped my top speed, allowing me to swim with the better swimmers without getting in their way, also adding to the enjoyment.

A lot of swimmers do interval training too - eg 20 by 4 lengths every X minutes (with X including some rest time) - as you get better you drop the minutes to give yourself less rest and can up the number of intervals too.

I guess its all down to enjoyment to swim more efficiently, as you counter the energy savings by going faster and longer ... Its like the pleasure you get from programming in a language you are expert in vs the one your just learning (which is rather frustrating until you get good at it and don't need the manual every two minutes!).

But you may learn more in the new language. (Like swimming badly burns more energy.)

Total Immersion really is an excellent program. It brought me from totally incompetent to competing on my high school's varsity team within the space of a couple months. I never expected to see it mentioned on news.yc.

Actually, though, you don't need to have good technique to get a good workout from swimming. In fact, I think swimming badly is significantly better exercise than swimming well.

But is it as much fun?

I really like swimming. But the chlorine compound (or whatever) in swimming-pool water affects my skin. So I can't swim regularly.

I've found a sauna helps by sweating the compound out of my skin.

Chlorine is by far the most common pool cleaner, but not the only option. Some pools use other methods like ozonation and UV sterilization. Neither of these would bother your skin. Pools like this are admittedly much harder to find, but if you really want to swim it might be worth the effort to track one down. I have a friend that bought an 'endless pool' that uses ozonation technology because of a chlorine allergy.

If you use soap and shampoo that are specially formulated to remove chlorine after you swim, it will also help you immensely. Most of the bad effects of chlorine for your skin are from longer-term exposure. Of course, you still have the carcinogen issue...but you can minimize that somewhat by swimming in a cooler temp pool with cool ambient air.

Thanks for that.

Your comment prompted me to find this international list of non- and low-chlorine pools: http://piscinasana.blogspot.com/ .

Where do you live? You can swim safely in almost any random pond.

That is probably true, but a lot of it depends on the care you take while running.

Advice to anyone who runs on anything besides grass or rubberized tracks: buy expensive running shoes ($80+) fitted to you by a someone who knows what they are doing. A sales person at a specialty running store should be qualified.

Or go barefoot.

Once you know what kind of shoes you need (from a specialist or something), go to runningwarehouse.com and use the coupon code CP20 (corporate perks 20% off coupon). That can make a $90 shoe like $65-70 because their shoes are already like 10-20% off to begin with. No discount for asics or mizuno though :(

They've found higher correlation of intelligence with cardio vs. anaerobic. Although that just may be a function of what kind of person prefers running and swimming as opposed to throwing weights around.

I prefer the latter.

From page 2:

"The study also showed that people cannot use the risk of injury as an excuse not to run -- the runners had fewer injuries of all kinds, including to their knees."

In fact, other papers I've read have said that runners and cross-country skiers maintain bone density and joint lubrication into old age, while swimmers and cyclers do not.

Ah but that has a lot to do with not knowing what shoes to buy. I'm a distance runner, used to get injured a lot, now I wear the right shoes and do 10+ miles a day at 6:00-7:00 mile pace. The key is having a group/friends to run with and enough discipline to do it every day.

Swimming is awesome also, but running is easier to do because you don't need a pool or a club to do it.

This is a very good point. It reminds me of a study I saw years ago that said runners generally also had better dental health. The point illustrated is that runners were more likely to floss! So it wasn't running that directly caused their better dental health, but you could say that it running and flossing have some correlation.

I'll try to dig up a link.

Well, I couldn't find that link... but I did discover something equally interesting along the way: check out http://www.centerforintegrativedentistry.com/gum_disease/ind... and scroll down to the "oxygenation" section.

It seems that the more exercise you get, the more oxygenated your gums are, and (gum disease) germs survive better the less oxygen there is- so marathon runners have an extremely low incidence rate of gum disease! wow.

Intriguingly, bike shops do not sell long sleeve tops (that protect you from sunburn) - but surf shops do. Cyclists have told me that they don't get sunburn - even when cycling in the sun all day. But surfers do get sunburn. I'm not sure what to make of this.

I'm theorizing that cyclists are somehow protected by constant movement (unlike surfers waiting for a wave). Perhaps the airflow is protective? Or perhaps it makes cyclists aerobically fitter, and this makes their skin more resistant to sunburn (and therefore skin cancer).

I'm an avid cyclist and I can sunburn easily if I don't use sunblock. I would say that surfers are more likely to burn (and do so more quickly) simply because beaches don't have much shade. While riding a bicycle you can often duck into tree shadows during a ride.

Some cyclists do use long-sleeve summer jerseys, but they're in the minority. Short sleeve and sleeveless jerseys are more popular because they are cooler.

The explanation is much simpler: You burn much faster on or in the water because of the reflections from the water...you're basically sitting on a giant mirror.

I fried myself once when I was sailing, and I had the worst burns on the bottom parts of my body (bottom of chin, bottom of knees, basically anywhere the rays hit me after bouncing off the water.)

The problems are a little more subtle than that, I think. The study was of middle aged runners and non-runners over a 20 year period. It didn't include any elderly, apparently. So the anti-correlation here is between death in middle age (what most people would term "dying early") and running. There is no correlation shown for the lede of the article, which talks about living a "long life". There's evidence that runners don't die young as often, not that they live longer.

As far as causation goes, I don't have too much of a problem with that. The clear hypothesis would be that runners have stronger hearts more capable of dealing successfully with degenerative conditions like heart disease, and therefore they're less likely to die of a very common killer of the middle aged. The hypothesis isn't proven by the data at hand, but is at least very strongly suggested.

This reminds me of:

Dr. House: "Excuse me miss, do you have cancer?" [Woman shakes her head] Dr. House: "Wow. Mango juice prevents cancer"

You are right to not read too much into this study but that doesn't mean it is not worthwhile. An epidemiological study - especially this one with a small sample size and based on self reporting - cannot prove causation. Still, the study should be enough to justify a closer look.

normally, we do a regression on this behavior alone to conclude this. This is epidemiology research, it singles one factor.

Reply on news.ycombinator.com