Maxing Out: Too Much Running, Vitamin D, and Calcium?


Is it possible to get too much Vitamin D? Will you live longer if you don't run too fast or too far? And should you stop taking those calcium supplements your doctor has been hounding you about for decades?

Yep, as is often the case, new studies are coming out just to f--ck with your head suggesting that conventional wisdom about exercise and nutrition may be more complicated than previously thought.


But Wait... Why Are We So Surprised And Annoyed?

Or maybe it's just me who hates the notion of upper limits. Anyway, before going into any specifics, let me take a step back and remind myself:

Just because SOME is good, does not mean MORE is better.

Duh, right? Most things in life do not work that way.

Thirsty?

Well perhaps there are a few exceptions...


Really, is that all you got?

Yet when it comes to health and fitness, there is so much nagging out there that it's easy to internalize the message: Whatever you're doing, it's not enough.

Are you getting enough nutrients in your food for optimum health? IMPOSSIBLE!  Are you exerting yourself strenuously enough, long enough, and frequently enough to ensure longevity?  OF COURSE NOT, YOU NEED TO DO MORE!

And yet, strangely enough, health and fitness turns out to be very much like any other human endeavor. Moderation tends to be more optimal than extremes.

Well I dunno, looks totally fun to me.

But sure enough, it turns out that human bodies seem to have a sweet spot for most things, and there is such thing as too much of anything.  And yes, even "good" things like physical exertion and nutrients. Hell, there are probably even downsides to too much tranquility and bliss! Though I personally wouldn't mind being a guinea pig in a perpetual bliss experiment.  Scientists? Hey Scientists? Hello?

Anyway, on to a few brief specifics and links.  Other folks, as usual, have way better coverage and analysis than I'm gonna bother with.

Too Much Running?


According a press release about excessive endurance training and a study on running and mortality risk  (all discussed much more sensibly by Alex Hutchinson at Runner's World) : While some running is great for you--and it's way more exercise than the average person gets--more is not necessarily better.

Some key points:

  • The majority of health benefits from exercise "accrue at a relatively modest level...beyond 30-60 minutes per day, you reach a point of diminishing returns."
  • Running distances of up to 20 miles/week, speeds of 6-7 miles/hour, and frequencies of 2-5 days/week was associated with a lower risk of all-cause mortality compared to non-runners.
  • But higher mileage, faster paces, and more frequent running were not associated with better survival. In fact, there was a U-shaped mortality curve for distance, speed, and frequency.  In plain English:  more of the extreme superhuman kickass runners croaked over a 15 year period than regular runners.
  • Extreme endurance exercise (i.e. marathons, iron man triathlons, extreme bicycle races) "may cause structural changes to the heart and large arteries, leading to myocardial injury."
  • Endurance sports participants may be up to five times more likely to suffer from atrial fibrillation, and extreme training may be linked to "coronary artery calcification, diastolic dysfunction, and large-artery wall stiffening."

Be warned, exercise junkies!

Excessive Vitamin D?


You wouldn't think it was possible given all the hype, but sure enough, extremely high blood levels of Vitamin D are unhealthy and lead to higher mortality. (Note: this was also cribbed from Alex, 'cause hell, I was already there at his blog and I'm lazy like that).

What are optimal levels?

The lowest mortality risk was at 50-60 nmol/liter.

(And what's an nmol? Simple! It's a scientific measure of the precise amount of, um, nmoleness in every liter. You're welcome).

Here's a cool graph from the press release, let's hope the researchers don't chase me down and sue me:


Health Dangers of Calcium Supplementation


I think there was an earlier study that said "watch out!" too, but I kinda ignored it because I figured there was a good chance the study would get contradicted again in a few weeks. But alas, it seems that while you can get calcium safely from food, calcium supplementation is linked to heart problems.

Here's the deal: a moderate intake of calcium (820 milligrams per day) was associated with a 30 % lower risk of a heart attack than a low intake. And it didn't help to consume more than 1,100 milligrams a day.

But here's the scary part: People who got their calcium almost exclusively from supplements were more than twice as likely to have a heart attack as those who took no supplements.

Yikes!

So how do you vegans and lactose intolerant folks handle this? Personally, I've switched to goat milk, as I'm finding as I get older I seem to be a bit intolerant of the ol' cow juice. So I can still easily get calcium from my diet and have decided to ditch the supplements.

Now I know theoretically there are non-animal calcium sources, but many of these turn out to be "fortified" foods. And isn't "fortification" just a butcher, muscle-bound euphemism for "supplementation?"

Or, well, I guess it helps if you just LOVE blackstrap molasses and collard greens!

And on a totally unrelated note:

What About the Freakin' Booty Camp Winner?

There isn't one yet!  So if you missed the Booty Camp Giveaway, there's still a couple of days to enter or increase your chances to win.   The set has 11 DVD's for a lot of different workouts, plus extra bonus thingies.

All you have to do is skim past a bunch of self-serving life coaching propaganda and leave a comment on the post.  (And there are additional ways to boost your chances).  And who knows, maybe you'll feel brainwashed  inspired to take advantage of one of the (cheap!) coaching slots still open and totally get your life together this summer and live happily ever after. Or whatever!  Anyway, the giveaway winner will be chosen approximately Wednesday morning.  Good Luck!

So what do you guys think, are you "moderate" in all things or do you sometimes go with the  "more must be better" philosophy?

Photos credits:  Vitamin D Poster; Hirschhorn Exhibit; Chocolate; Exhausted Runner.

Tidak ada komentar:

Posting Komentar