Category Archives: Aging Muscles
>The Truth Behind 7 Muscle Myths
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By: Scott Quill
The guy lifting beside you looks like he should write the book on muscle. Talks like it, too. He’s worked out since the seventh grade, he played D-1 football, and he’s big.
But that doesn’t mean he knows what he’s talking about. Starting now, ignore him.
The gym is infested with bad information. Lies that start with well-intentioned gym teachers trickle down to students who become coaches, trainers, or know-it-all gym-rat preachers. Lies morph into myths that endure because we don’t ask questions, for fear of looking stupid.
Scientists, on the other hand, gladly look stupid—that’s why they’re so darn smart. Plus, they have cool human-performance laboratories where they can prove or disprove theories and myths.
Here’s what top exercise scientists and expert trainers have to say about the crap that’s passed around in gyms. Listen up and learn. Then go ahead, question it.
Slow Lifting Builds Huge Muscles
Lifting super slowly produces superlong workouts—and that’s it. University of Alabama researchers recently studied two groups of lifters doing a 29-minute workout. One group performed exercises using a 5-second up phase and a 10-second down phase, the other a more traditional approach of 1 second up and 1 second down. The faster group burned 71 percent more calories and lifted 250 percent more weight than the superslow lifters.
The real expert says: “The best increases in strength are achieved by doing the up phase as rapidly as possible,” says Gary Hunter, Ph.D., C.S.C.S., the lead study author. “Lower the weight more slowly and under control.” There’s greater potential for growth during the lowering phase, and when you lower with control, there’s less chance of injury.
More Protein Builds More Muscle
To a point, sure. But put down the shake for a sec. Protein promotes the muscle-building process, called protein synthesis, “but you don’t need exorbitant amounts to do this,” says John Ivy, Ph.D., coauthor of Nutrient Timing.
If you’re working out hard, consuming more than 0.9 to 1.25 grams of protein per pound of body weight is a waste. Excess protein breaks down into amino acids and nitrogen, which are either excreted or converted into carbohydrates and stored.
The real expert says: More important is when you consume protein, and that you have the right balance of carbohydrates with it. Have a postworkout shake of three parts carbohydrates and one part protein.
Eat a meal several hours later, and then reverse that ratio in your snack after another few hours, says Ivy. “This will keep protein synthesis going by maintaining high amino acid concentrations in the blood.”
Squats Kill Your Knees
And cotton swabs are dangerous when you push them too far into your ears. It’s a matter of knowing what you’re doing.
A recent study in Medicine & Science in Sports & Exercise found that “open-chain” exercises—those in which a single joint is activated, such as the leg extension—are potentially more dangerous than closed-chain moves—those that engage multiple joints, such as the squat and the leg press.
The study found that leg extensions activate your quadriceps muscles slightly independently of each other, and just a 5-millisecond difference in activation causes uneven compression between the patella (kneecap) and thighbone, says Anki Stensdotter, the lead study author.
The real expert says: “The knee joint is controlled by the quadriceps and the hamstrings. Balanced muscle activity keeps the patella in place and appears to be more easily attained in closed-chain exercises,” says Stensdotter.
To squat safely, hold your back as upright as possible and lower your body until your thighs are parallel to the floor (or at least as far as you can go without discomfort in your knees).
Try front squats if you find yourself leaning forward. Although it’s a more advanced move, the weight rests on the fronts of your shoulders, helping to keep your back upright, Stensdotter says.
Never Exercise a Sore Muscle
Before you skip that workout, determine how sore you really are. “If your muscle is sore to the touch or the soreness limits your range of motion, it’s best that you give the muscle at least another day of rest,” says Alan Mikesky, Ph.D., director of the human performance and biomechanics laboratory at Indiana University-Purdue University at Indianapolis.
In less severe instances, an “active rest” involving light aerobic activity and stretching, and even light lifting, can help alleviate some of the soreness. “Light activity stimulates bloodflow through the muscles, which removes waste products to help in the repair process,” says David Docherty, Ph.D., a professor of exercise science at the University of Victoria in Canada.
The real expert says: If you’re not sore to the touch and you have your full range of motion, go to the gym. Start with 10 minutes of cycling, then exercise the achy muscle by performing no more than three sets of 10 to 15 repetitions using a weight that’s no heavier than 30 percent of your one-rep maximum, says Docherty.
Stretching Prevents Injuries
Maybe if you’re a figure skater. Researchers at the Centers for Disease Control and Prevention reviewed more than 350 studies and articles examining the relationship between stretching and injuries and concluded that stretching during a warmup has little effect on injury prevention.
“Stretching increases flexibility, but most injuries occur within the normal range of motion,” says Julie Gilchrist, M.D., one of the study’s researchers. “Stretching and warming up have just gone together for decades. It’s simply what’s done, and it hasn’t been approached through rigorous science.”
The real expert says: Warming up is what prevents injury, by slowly increasing your bloodflow and giving your muscles a chance to prepare for the upcoming activity. To this end, Dr. Gilchrist suggests a thorough warmup, as well as conditioning for your particular sport.
Of course, flexibility is a good thing. If you need to increase yours so it’s in the normal range (touching your toes without bending your knees, for instance), do your stretching when your muscles are already warm.
Use Swiss Balls, Not Benches
Don’t abandon your trusty bench for exercises like the chest press and shoulder press if your goal is strength and size. “The reason people are using the ball and getting gains is because they’re weak as kittens to begin with,” says Craig Ballantyne, C.S.C.S. You have to reduce the weight in order to press on a Swiss ball, and this means you get less out of the exercise, he says.
The real expert says: A Swiss ball is great for variety, but center your chest and shoulder routines on exercises that are performed on a stable surface, Ballantyne says. Then use the ball to work your abs.
Always Use Free Weights
Sometimes machines can build muscle better—for instance, when you need to isolate specific muscles after an injury, or when you’re too inexperienced to perform a free-weight exercise.
If you can’t complete a pullup, you won’t build your back muscles. So do lat pulldowns to develop strength in this range of motion, says Greg Haff, Ph.D., director of the strength research laboratory at Midwestern State University in Wichita Falls, Texas.
The real expert says: “Initially, novice athletes will see benefits with either machines or free weights, but as you become more trained, free weights should make up the major portion of your training program,” says Haff.
Free-weight exercises mimic athletic moves and generally activate more muscle mass. If you’re a seasoned lifter, free weights are your best tools to build strength or burn fat.
Fit heart can slow brain ageing, US researchers say
Clock Turned Back on Aging Muscles, Researchers Claim
Scientists have found and manipulated body chemistry linked to the aging of muscles and were able to turn back the clock on old human muscle, restoring its ability to repair and rebuild itself, they said today.
The study involved a small number of participants, however. And the news is not all rosy.
Importantly, the research also found evidence that aging muscles need to be kept in shape, because long periods of atrophy are more challenging to overcome. Older muscles do not respond as well to sudden bouts of exercise, the scientists discovered. And rather than building muscle, an older person can generate scar tissue upon, say, lifting weights after long periods of inactivity.
The findings are detailed today in the European journal EMBO Molecular Medicine.
“Our study shows that the ability of old human muscle to be maintained and repaired by muscle stem cells can be restored to youthful vigor given the right mix of biochemical signals,” said study leader Irina Conboy of the University of California, Berkeley. “This provides promising new targets for forestalling the debilitating muscle atrophy that accompanies aging, and perhaps other tissue degenerative disorders as well.”
More research would be needed before any anti-aging products might result from the work, however.
Strong mysteries
Scientists know that muscles deteriorate rapidly in old age. Mechanisms that prevent muscle breakdown work less effectively in people over the age of 65, a study earlier this month found. Other research has shown that neurons have to yell louder to kick aging muscles into gear.
Yet much about how and why muscles respond to exercise, and atrophy without it, remains unknown.
Previous research in animal models led by Conboy revealed that the ability of adult stem cells to do their job of repairing and replacing damaged tissue is governed by the molecular signals they get from surrounding muscle tissue, and that those signals change with age in ways that thwart tissue repair. But the animal studies also showed that the regenerative function in old stem cells can be revived.
Meanwhile, there is no fountain of youth for aging muscles. The best advice for now: Eat well and exercise regularly throughout life.
Human muscle atrophy
In the new study, a team of researchers compared samples of muscle tissue from nearly 30 healthy men. The young group ranged from age 21 to 24 and averaged 22.6 years old, while the older group averaged 71.3 years old, ranging from 68 to 74.
Muscle biopsies were taken from one quadriceps (upper leg muscle) of each test subject, who then had that leg immobilized in a cast for two weeks to simulate muscle atrophy. After the casts were removed, the men lifted weights to regain muscle mass. More muscle tissue samples were taken.
Analysis showed that before the legs were immobilized, the adult stem cells responsible for muscle repair and regeneration were only half as numerous in the old muscle as they were in young tissue. (Muscle stem cells produce other muscle cells.) The disparity increased during exercise, with younger tissue having four times more regenerative cells compared with the old muscle.
Muscles of the older participants showed signs of inflammation and scar tissue formation during immobility and again four weeks after the cast was removed.
“Two weeks of immobilization only mildly affected young muscle, in terms of tissue maintenance and functionality, whereas old muscle began to atrophy and manifest signs of rapid tissue deterioration,” said Morgan Carlson, another UC Berkeley researcher and the study’s lead author.
“The old muscle also didn’t recover as well with exercise,” Carlson said. “This emphasizes the importance of older populations staying active because the evidence is that for their muscle, long periods of disuse may irrevocably worsen the stem cells’ regenerative environment.”
The researchers warned that in the elderly, rigorous exercise after immobility can cause replacement of functional muscle by scarring and inflammation.
“It’s like a Catch-22,” Conboy said.
Restoring powers
Previous studies have shown that adult muscle stem cells have a receptor called Notch, which triggers growth when activated. Those stem cells also have a receptor for the protein TGF-beta that, when excessively activated, sets off a chain reaction that ultimately inhibits a cell’s ability to divide. In aging mice, the decline of Notch and increased levels of TGF-beta ultimately block the stem cells’ ability to rebuild muscle.
The new study found the same process at work in humans. But it also revealed that an enzyme called mitogen-activated protein kinase (MAPK) regulates Notch activity.
In old muscle, MAPK levels are low, so the Notch pathway is not activated and the stem cells no longer perform their muscle regeneration jobs properly, the researchers said.
In the lab, the researchers cultured old human muscle and forced the activation of MAPK. The regenerative ability of the old muscle was significantly enhanced, they report.
“In practical terms, we now know that to enhance regeneration of old human muscle and restore tissue health, we can either target the MAPK or the Notch pathways,” Conboy said. “The ultimate goal, of course, is to move this research toward clinical trials.”
The research was supported by the National Institutes of Health, the California Institute of Regenerative Medicine, the Danish Medical Research Council and the Glenn Foundation for Medical Research.
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