Isegoria

Fitness orthodoxy shifts slowly. New research demonstrates that sprints may be best for diabetes prevention:

Timmons and his team found that young sedentary men who did just 15 minutes of all-out sprinting on an exercise bike spread out over two weeks substantially improved their ability to metabolize glucose (sugar). Traditional aerobic exercise programs can boost sensitivity to the key blood-sugar-regulating hormone insulin. The high-intensity program did this too, but it also directly reduced the men’s blood sugar levels — something that standard exercise programs have not been shown to do.

A new procedure uses athletes’ own blood to treat injuries by injecting the “growth-factor cocktail” right where it’s needed — including poorly vascularized tissues, like ligaments and tendons:

Platelet-rich plasma is derived by placing a small amount of the patient’s blood in a filtration system or centrifuge that rotates at high speed, separating red blood cells from the platelets that release proteins and other particles involved in the body’s self-healing process, doctors said. A teaspoon or two of the remaining substance is then injected into the damaged area. The high concentration of platelets — from 3 to 10 times that of normal blood — often catalyzes the growth of new soft-tissue or bone cells. Because the substance is injected where blood would rarely go otherwise, it can deliver the healing instincts of platelets without triggering the clotting response for which platelets are typically known.

“This could be a method to stimulate wound healing in areas that are not well-vascularized, like ligaments and tendons,” said Dr. Gerjo van Osch, a researcher in the department of orthopedics at Erasmus University Medical Center in the Netherlands. “I call it a growth-factor cocktail — that’s how I explain it.”

Dr. van Osch and several other experts said they had used the procedure as a first option before surgery for reasons beyond its early results. There is little chance for rejection or allergic reaction because the substance is autologous, meaning it comes from the patient’s own body; the injection carries far less chance for infection than an incision and leaves no scar, and it takes only about 20 minutes, with a considerably shorter recovery time than after surgery.

Because of those apparent benefits, the consensus among doctors is that the procedure is worth pursuing. However, several doctors emphasized that platelet-rich plasma therapy as it stands now appeared ineffective in about 20 to 40 percent of cases, depending on the injury. But they added that because the procedure costs about $2,000 — compared with $10,000 to $15,000 for surgery — they expected that with more refinement, insurance companies would eventually not only authorize the use of PRP therapy but even require it as a first course of treatment.

America’s diet is too sweet by the spoonful, Jane Brody says, but we shouldn’t be especially worried about high-fructose corn syrup, because it isn’t too terribly different from table sugar:

High-fructose corn syrup is made by converting the starch in corn to a substance that is about 90 percent fructose, a sugar that is sweeter than the sugar that fuels the body cells, called glucose, and processed differently by the body. The fructose from corn is then mixed with corn syrup, essentially pure glucose, to produce one of two mixtures called high-fructose corn syrup: 55 percent fructose and 45 percent glucose, which is used to sweeten soft drinks, and 42 percent fructose and 58 percent glucose, which is used in products like breads, jams and yogurt.

Neither substance is radically different from ordinary sugar, which is 50 percent fructose and 50 percent glucose. The main difference is that in high-fructose corn syrup, the two sugar molecules are chemically separated, and in sucrose they are linked. Whether this difference is meaningful to health is still debated.

People still seem to associate exercise volume with health and fitness, when it really takes surprisingly little time in the gym — or outside — to get fit. Want to get healthy? Exercise 7 minutes a week:

Timmons and his team showed that just seven minutes of exercise each week helped a group of 16 men in their early twenties control their insulin.

The volunteers, who were relatively out of shape but otherwise healthy, rode an exercise bike four times daily in 30 second spurts two days a week.

After two weeks, the young men had a 23 percent improvement in how effectively their body used insulin to clear glucose, or blood sugar, from the blood stream, Timmons said.

The effect appears to last up to 10 days after the last round of exercise, he added in a telephone interview.

In Stretching: The Truth, the New York Times finally gets around to sharing a basic fitness fact — stretching is not the same as warming up:

Researchers now believe that some of the more entrenched elements of many athletes’ warm-up regimens are not only a waste of time but actually bad for you. The old presumption that holding a stretch for 20 to 30 seconds — known as static stretching — primes muscles for a workout is dead wrong. It actually weakens them. In a recent study conducted at the University of Nevada, Las Vegas, athletes generated less force from their leg muscles after static stretching than they did after not stretching at all. Other studies have found that this stretching decreases muscle strength by as much as 30 percent. Also, stretching one leg’s muscles can reduce strength in the other leg as well, probably because the central nervous system rebels against the movements.

Instead, modern experts recommend dynamic stretches — which, years ago, we were all told were dangerous. Sigh.

Physicist often show A Passion for Physical Realms, Minute and Massive — abstract and concrete:

At almost any physics workshop or conference there is likely to be a cluster of alpine adventurers whose passion for exploring the wilderness of abstractions also sends them off to ascend granite cliffs or scramble up fields of boulders at 14,000 feet.

“Climbing and physics both bring an intimacy with nature,” said Dr. Steven B. Giddings, a physicist at the University of California at Santa Barbara, who studies the peculiarities of black holes. “In physics this comes through unraveling the deepest secrets of how nature works, and in climbing by facing the unfolding challenges of an ascent through unknown territory.”
[...]
“When I was a student in Cambridge, about half the University Mountaineering Club was either mathematicians or physicists,” said Dr. John Cardy, a theoretical physicist at Oxford who recently joined a trek in the Himalayas. “In the present local club of which I am part, there is still a preponderance of people with a training in physics.”
[...]
“One of the difficulties of theoretical physics is the intangibility of the subject,” Dr. Giddings said. “In climbing, the challenges are tangible to the point that small decisions can dictate your survival.”
[...]
Over the years physicists have given their names not only to the phenomena of physics but also to routes up obstacles of rock. Theorists at CERN, the leading European particle physics laboratory, refer to the Sacherer frequency and the Sacherer method for computing something called “bunched-beam instabilities” in a particle accelerator. And climbers in Yosemite tackle the Sacherer Cracker, part of a route up the treacherous El Capitan. All these landmarks were named for Dr. Frank J. Sacherer, a theoretical physicist at CERN, who was a world-class expert on the behavior of particle accelerators.

Climbers in the Shawangunk Mountains north of New York City might find themselves trying to negotiate Shockley’s Ceiling, named for Dr. William B. Shockley, the Bell Laboratories researcher who shared a Nobel Prize for Physics in 1956 for the development of the transistor. Another enthusiastic Shawangunk climber, also at the laboratories, was Dr. Lester Germer, who collaborated with Dr. Clinton J. Davisson in 1927 to show that electrons can act like waves, as quantum theory predicted.

In his memoir “Mountain Passages,” Dr. Jeremy Bernstein, a physicist, remembered a close call when he was negotiating the Cosmic Spur, a challenging route up the south face of the Aiguille du Midi in the French Alps. It is named in honor of an old laboratory where, earlier in the century, experimenters — some of the first physicist-mountaineers — snatched cosmic rays falling from the sky to study the nature of particles.

With the help of his guide, Dr. Bernstein avoided a fall. But some physicists have lost their lives in the mountains. Dr. Sacherer and a young theorist, Dr. Joseph H. Weis, died in 1978 when a storm struck while they were descending a hanging ice field called the Shroud on the Grandes Jorasses near Chamonix.

In 1988 the Rockefeller University theorist Dr. Heinz R. Pagels fell to his death while hiking down 14,000- foot Pyramid Peak, near Aspen. Dr. David N. Schramm, a cosmologist/ physicist whose climbing exploits earned him the nickname Schrambo, did not die on a mountain; he was killed when the Cessna he was flying to Aspen in 1997 crashed into a Colorado wheat field. But he had survived close calls in treacherous ascents on four continents.

Three to four hours of exercise trump the FTO obesity gene, according to a recent study of Amish men:

Researchers focused their study on a group of 704 Old Order Amish men and women in Lancaster County, Pennsylvania, a religious group whose members often do not drive cars or have electricity in their homes.

Snitker said the group offered a unique mix of activity levels, with some farmers in the community still using horse-drawn plows while others holding more conventional jobs, including factory work.

He and colleague Evadnie Rampersaud of the University of Miami were looking to see if physical activity in this group might offset the effects of the fat mass and obesity associated with the FTO gene, found in more than half of all people of European descent.

People with two copies of the FTO gene on average weigh nearly 7 pounds (3 kg) more and are about 70 percent more likely to be obese than those who do not have the gene.

The volunteers wore a device called an accelerometer to track motion for a week.

The researchers compared body mass index or BMI, a measure of weight to height, and found those who were less active and had the FTO gene variant were significantly more likely to be overweight or obese.

But among the most physically active, the FTO gene made no difference.

Snitker said the study gives some perspective on how the obesity epidemic has evolved, as modern conveniences have reduced the need and opportunity for physical activity.

People in the most physically active group expended about 900 more calories per day than the low-activity group. That would equal three to four hours of moderately intense physical activity such as brisk walking, house cleaning or gardening.

“We probably carry genes that 150 years ago were not risk factors for obesity, but because of changes in our environment, they become liabilities,” he said.