Showing posts with label health. Show all posts
Showing posts with label health. Show all posts

2010-01-18

Why cardio exercise has diminishing returns after a few weeks

J.D. Johannes explains why it's so hard to lose weight by doing only distance running:
How can something so logical as burning more calories through cardiovascular exercise not result in sustained fat loss? The answer is in your body’s ability to adapt to exercise and the complex functions of the hormone cortisol.
To lose weight and firm up muscle tone, one apparently needs to mix in interval/sprint training:
you alternate between periods of high intensity and low intensity. . .
The primary advantage of [this], especially short sprints outdoors, is the recovery/repair signal sent to the muscles. A sprint is almost like a weight lifting set--a short burst of maximal effort involving the fast twitch muscle fibers--followed by a period of rest.
This reasoning matches my experience very well, and agrees nicely with a book I recommend highly, Run Less, Run Faster.

via Glenn

2009-10-01

Cause of obesity? The yin-yang of spring and fall fats

Amazing if true department. Susan Allport author of The Queen of Fats, writes:
the essential fats—the omega-3s and their close cousins, the omega-6s—change with the seasons. It might sound like a small idea, but it may soon fundamentally change the way you think about food.
Omega-3s:
are likely the most abundant fats in the world, but they don't originate in fish, as many believe. Rather, they are found in the green leaves of plants. Fish are full of omega-3s because they eat phytoplankton [...] and seaweed. [...] The spring fats speed up metabolism. They are fats that animals (humans included) use to get ready for times of activity, like the mating season. They're found in the highest concentrations in all the most active tissues: brains, eyes, hearts, the tails of sperm, the flight muscles of hummingbirds. [...] These fats protect our brains from neurological disorders and enable our hearts to beat billions of times without incident.
Omega-6s:
originate in plants as well, but in the seeds of plants rather than the leaves. The fall fats are simply storage fats for plants.
Yin-yang:
Animals require both—omega-3s and omega-6s—in their diets and their tissues. But omega-6s are slower and stiffer than omega-3s. Plus, they promote blood clotting and inflammation, the underlying causes of many diseases, including heart disease and arthritis. Omega-3s, on the other hand, promote blood flow and very little inflammation, which may prevent things like heart disease. The proper mix of these two fats helps create tissue with the right amount of blood flow and inflammation.
The imbalance:
because they're in constant competition to enter our cells, if your diet consists of too many omega-6s, your body will be deficient in omega-3s. And that is what's been happening to us as we've been eating more and more seed fats in the form of soybean, corn and other vegetable oils.
The problem & the result:
Since 1909, according to the USDA, Americans have more than doubled their daily intake of omega-6s—from about 7 grams to around 18. One hundred years ago, heart disease was much less common in this country. Over the past century, though, heart disease has risen in tandem with our increasing intake of these seed fats, or omega-6s, according to the American Heart Association (AHA). So have neurological disorders like Lisa's, as well as depression, arthritis, obesity, insulin resistance and many cancers.
I don't know if all of this is true or not, but it sure seems to make sense to me, and probably Occam too.

Allport gives advice at the end of the article on how to increase Omega-3s and reduce Omega-6s in your diet.

Via Glenn Reynolds