Wednesday, December 30, 2009
Monday, December 28, 2009
Saturday, December 26, 2009
Friday, December 25, 2009
Wednesday, December 23, 2009
Tuesday, December 22, 2009
Sunday, December 20, 2009
Saturday, December 19, 2009
Thursday, December 17, 2009
Tuesday, December 15, 2009
Monday, December 14, 2009
Ready to Exercise? Check Your Watch
By GINA KOLATA
Published: December 9, 2009
MY friend Jen Davis and I often run together in the morning because it can be easier to fit in a run before work than after. But we always thought we ran better in the evening.
Then I accidentally discovered something weird. I took a spinning class one Thursday night, and my heart rate, measured by a monitor strapped around my chest, soared. I don't usually use a heart-rate monitor, but with stationary bikes, heart rate is pretty much the only way to know how hard you are working. And that night, my high heart rate told me it really was a tough workout.
The next morning I did a workout in my garage on a trainer — a device that holds a road bike, turning it into a stationary bike and yet allowing you to use its gears. My heart rate was about 15 beats a minute lower than it had been the night before. It seemed like a pitiful workout.
So the next night I got on the trainer again. I had the same playlist (I use music to set my cadence). I used the same gears for each song. And during the hourlong workout, my average heart rate and my maximum heart rate were about 15 beats a minute higher than they'd been the morning before.
I tried again the next morning. My heart rate was low. Intrigued, I tried my experiment for a week, alternating between early morning and early evening workouts. I got really sick of that playlist, but I wanted to control every variable.
And the pattern persisted: high heart rate at night, low in the morning for the identical workout. Once I even tried the workout in midday — that time, my heart rate was in between.
Could it be that I actually was a more efficient athlete in the morning, doing the same work but with less effort, as measured by a lower heart rate?
Jen reminded me that we'd seen the heart-rate effect last year but had not appreciated it. I had a stress fracture and was confined to pool running, which involves sprinting in the deep end of a pool. Your feet never touch the bottom. It was hard to gauge how hard we were working, so Jen and I wore heart rate monitors, just as we do in spinning classes.
We did the pool workouts together, and neither of us got our heart rates as high as we wanted in the morning. Evenings were fine, though. We thought we were just sluggish in the morning.
I also asked some friends who use heart rate monitors if they'd noticed anything like what I'd experienced.
Tara Martin, a triathlete, said she could never get her heart rate up in the morning.
Richard Friedman, a swimmer, said his heart rate was always lower in the morning. His swim team does the same workout in the morning as in the evening, and he swims it just as fast. He had assumed that somehow he was just not putting in the same effort early in the day. "Still," he said, "I'm pretty energetic all the time."
I asked Dr. William Haskell, an exercise researcher and emeritus professor of medicine at Stanford, if I'd stumbled on a known fact about heart rates. But he was baffled. Maybe I didn't have caffeine in the morning? So I tried taking NoDoz before the next morning workout. It made no difference.
Dr. William Roberts, a former president of the American College of Sports Medicine and a family physician at the University of Minnesota, said it was a "tough question." He added, "I do not have a good physiologic explanation for the phenomenon you are describing."
But, it turns out, a small group of researchers has studied the question of exercise performance and time of day, even doing studies of heart rates. And not only are performances better in the late afternoon and early evening, but, contrary to what exercise physiologists would predict, heart rates are also higher for the same effort.
One recent study, by the late Thomas Reilly and his colleagues at the Research Institute for Sport and Exercise Sciences at Liverpool John Moores University in England, found that people's maximum heart rates and sub-maximal heart rates were lower in the morning but that their perception of how hard they were working was the same in the morning as it was later in the day.
Dr. Reilly and his colleague Jim Waterhouse, in a review published this year, also noted that athletes' best performances, including world records, were typically set in the late afternoon or early evening.
Greg Atkinson, also at Liverpool John Moores University, said that some researchers, noticing that heart rates during exercise were lower in the morning, reasoned the way I did — that people must be more efficient in the morning. It would mean that exercise was easier in the morning. Of course, it seemed harder to me, but I could have been deluding myself. Not really, Dr. Atkinson said. It actually is harder to exercise in the morning.
"Most components (strength, power, speed) of athletic performance are worst in the early hours of the morning," he wrote in an e-mail message. "Ratings of perceived exertion during exercise have generally been found to be highest in the early morning."
If you exercise later in the day, your muscles are more flexible and stronger and your heart and lungs are more efficient, said Michael H. Smolensky, an expert in chronobiology, the study of the body clock.
"Is a heart rate of 140 in the morning indicative of the same level of workout cost as in the afternoon?" asked Dr. Smolensky, a visiting professor at the University of Texas Health Sciences Center in Houston.
"I would say no," he added. "Exercise physiologists say you should be able to perform at the same level with a heart rate of 140 in the morning as in the afternoon or early evening. But chronobiologists say your capacity to generate and tolerate a higher heart rate is better later in the day."
"In the afternoon and evening," Dr. Smolensky said, "you are in a different biological state."
But, he added, all this applies to people who are regular exercisers, who work out vigorously three or more times a week. People who are not regular exercisers, Dr. Smolensky said, put much more strain on their hearts in the morning, making their heart rates higher then.
In fact, Dr. Smolensky added, people at risk for a heart attack should plan their workouts for late afternoon or early evening.
But if you are used to regular exercise, is it better to train in the early evening?
"I really don't know the answer," Dr. Smolensky said.
"My personal approach is to train when your biological efficiency is greatest, which means late afternoon or early evening for most people," he said. "Others say if you train when your biological efficiency is least you will get a harder workout."
Some elite athletes prefer morning workouts for reasons that have nothing to do with research studies.
Deena Kastor, who holds the American marathon record, said her former coach and mentor, Joe Vigil, insisted on morning workouts. He told her that there was more fluid between the vertebrae of the spine after a night in bed, Ms. Kastor said. And, she said, "fluid made your spine more forgiving and more able to absorb the pounding of running." She noted that she had been running in the morning for the last 13 years "with very little injury."
But when people compete, if, for example, they want a personal best time, they might want to seek out one of the few events that start late in the day. Or, even better, it might make sense for endurance events, like marathons, to start in the afternoon instead of the morning, when they almost always are held. Maybe they could be held later in the year, to avoid afternoon heat.
Dr. Smolensky agreed.
"Most marathons start early under the guise that it's cooler then," he said. "That needs to be looked at."
Sunday, December 13, 2009
Saturday, December 12, 2009
Thursday, December 10, 2009
Wednesday, December 9, 2009
The science: Human movement occurs on three different geometric planes:
1. The sagittal plane, for front-to-back and up-and-down movements
2. The frontal plane, for side-to-side movements
3. The transverse plane, for rotational movements
Most weight-lifting movements—the bench press, squat, curl, lunge, and chinup, to name a few—are performed on the sagittal plane; the balance of exercises—for instance, the lateral lunge and side bend—occur almost entirely on the frontal plane. This means that most men rarely train their bodies on the transverse plane, despite using rotation constantly in everyday life, as well as in every sport. Case in point: walking. It's subtle, but your hips rotate with every step; in fact, watch a sprinter from behind and you'll see that his hips rotate almost 90 degrees. By adding a rotational component to any exercise, you'll automatically work more muscle—since you'll fully engage your core, as well as the original target muscles—and simultaneously build a better-performing body.
Apply it: Simply twist your torso to the right or left in exercises such as the lunge, situp, and pushup. You can also rotate your hips during movements such as the reverse crunch.
The science: When you lower your body during any exercise, you build up "elastic energy" in your muscles. Just like in a coiled spring, that elasticity allows you to "bounce" back to the starting position, reducing the work your muscles have to do. Eliminate the bounce and you'll force your body to recruit more muscle fibers to get you moving again. How? Pause for 4 seconds in the down position of an exercise. That's the amount of time it takes to discharge all the elastic energy of a muscle.
Apply it: Use the 4-second pause in any exercise. And give yourself an extra challenge by adding an explosive component, forcefully pushing your body off the floor—into the air as high as you can—during a pushup, lunge, or squat. Because you're generating maximum force without any help from elastic energy, you'll activate the greatest number of muscle fibers possible.
Tuesday, December 8, 2009
Mark A W Andrews
Muscle cramping is a common problem encountered by athletes and nonathletes
alike. Defined as painful involuntary skeletal muscle contractions, cramps
may be categorized as either nonexercise related or exercise related. The
etiology of the former group may involve hormonal, electrolyte or metabolic
imbalances, or it may result from long-term medication. Diagnostic medical
testing may be required if cramps are a persistent problem. Exercise-related
muscle cramps (ERMC) are much more common. They typically affect the large
muscles of the legs during or immediately after exercise and last for seconds
to a few minutes. These are typically benign but result in intense pain and
may not seem innocuous at the time.
There is little definitive knowledge of the etiology of ERMC. Traditionally,
such cramping was believed to arise from dehydration, electrolyte imbalances
(including magnesium, potassium and sodium), accumulation of lactic acid, or
low cellular energy levels. These proposals, however, have been shown to have
minimal scientific value.
More recent developments indicate that the cause of cramps most likely
involves hyperactivity of the nerve-muscle reflex arc. In this scheme, some
of the normal inhibitory activity of the central nervous system (CNS)
reflexes is lost as a result of CNS fatigue or overuse of feedback
communication with muscles. These spinal reflexes use two receptors, known as
Golgi tendon organs and muscles spindles, found in skeletal muscles. Golgi
tendon organs may become inhibited and muscles spindles can become
hyperactive, leading to sustained activation of the muscle.
It has been suggested that prolonged sitting, poor or abnormal posture or
inefficient biomechanics (all of which may be related to poor flexibility)
predispose these reflexes to malfunctioning. Age also seems to predispose
individuals to cramping--the phenomenon may develop later in life for people
who exercise for years without prior problems. Other factors include
increased body weight and improper footwear. Eccentric muscle contraction and
other musculoskeletal injuries can contribute to the problem.
If a muscle's hyperexcitability is the basis of cramping, then stretching
should attenuate the response. In evidence, it is well recognized that, once
induced, stretching the affected muscle can ameliorate cramping. Stretches
should be held for 15 to 30 seconds or until the muscle relaxes and the cramp
does not recur when the muscle is returned to its normal relaxed position. In
addition, once cramping starts, exercise should be curtailed for at least an
hour, which allows the muscles and the CNS to recover. It is never a good
idea to "run through" these cramps. Applying heat to the area for a few
minutes while stretching may also help the muscle.
Prophylactic stretching of the major muscles of the lower limbs for at least
five to 10 minutes during warm-up and cool-down periods can help prevent
cramps. The importance of flexibility cannot be overstated, particularly for
older athletes. Other recommendations include minimizing running hills and
stairs (limiting eccentric contractions); undergoing a biomechanical
evaluation of your exercise technique; making sure shoes and other equipment
are appropriate and not excessively worn. If, after a few months, cramps do
not respond to these measures, see a qualified sports physician or physical
Sunday, December 6, 2009
Saturday, December 5, 2009
Thursday, December 3, 2009
Phys Ed: How to Prevent Stress Fractures
By GRETCHEN REYNOLDS
Stress fractures are one of the more pernicious injuries in sports, afflicting the experienced and the aspiring, with no regard for competitive timing. Last year, Tiger Woods managed to win the U.S. Open despite suffering from stress fractures in his left leg (as well as other leg and knee injuries), while the great British marathoner Paula Radcliffe struggled through the Beijing Olympics Marathon on a leg barely recovered from a stress fracture, one of several she’s suffered. The International Association of Athletics Federations, the world governing body for track and field, recently described stress fractures, with a kind of grim resignation, as “the curse of athletes.”
But studies published in this month’s issue of the journal Medicine & Science in Sports & Exercise offer hope that, at least for runners, simple alterations in their stride or in the strength of their legs might reduce their risk for the most common type of stress fracture.
In one of the studies, undertaken at the University of Minnesota, researchers recruited 39 competitive women runners, ages 18 to 35, and started measuring them. In particular, the scientists wanted to examine the size and shape of their shinbones, or tibias. About half of all stress fractures occur in the tibia, studies show. When you run or jump, that bone is pulled and bent. Sometimes, microscopic fissures form. In most cases, these tiny cracks heal quickly. But, sometimes, continued activity overwhelms the bone’s capacity to recover. The cracks grow and combine into a fracture.
The Minnesota researchers wanted to see whether the shinbones of the runners with a history of stress fractures were weaker than those without. Earlier studies suggested that this would be the case. But few studies have examined the size of the runners’ calf muscles. Bones tend to adapt to the muscles around them; puny muscles can mean puny bones. The Minnesota scientists, using a new machine that examines bone in three dimensions and measuring the runners’ leg muscles, found that, surprisingly, the injured runners’ bones were as strong, in relation to their muscle size as the bones in the uninjured runners. But the injured runners had significantly smaller calf muscles and therefore also slighter bones. The primary difference, the researchers concluded, between the women who suffered stress fractures and those who hadn’t was the size (and presumably strength) of their calf muscles.
This finding should be encouraging to anyone who has had a tibial stress fracture or would prefer not to. “It does seem as if strengthening the calf muscles may be a very easy way” to reduce fracture risk, says Moira Petit, an associate professor of kinesiology at the University of Minnesota and an author of the study. In addition, she said, “our data suggest that you don’t have to strengthen the muscle by much.” A small increase of bulk, achievable by, for instance, rising up on to your toes and sinking back to the floor 10 or 12 times every day, might be enough. Adding even a small amount of calf muscle “serves two purposes,” Ms. Petit says. First, “the strength of the bone will usually increase” in response to the added muscle. And, as a bonus, the new muscle “can absorb more” of the forces generated when you run. So even as the tibia strengthens in response to the new muscle, it also is subjected to less shock. “Really, there’s no downside to this,” Ms. Petit says.
Her results, though, may apply primarily to women; she’s studying male runners, but so far, she says, isn’t seeing the same relationship between their calf-muscle size and bone strength. The other study in the current Medicine & Science in Sports & Exercise, however, did focus on men and their stress fractures, although, in this case, the lead researcher suggests that the findings would be true in women as well. In the work, from Iowa State University in Ames, computer modeling was used to predict what would happen to stress fracture risk if runners changed their strides. The researchers attached reflective markers to the bodies of 10 former or current collegiate-level cross-country runners and had them run repeatedly down a runway nearly 30 meters long, making sure to step onto a force plate that measured how hard they were striking the ground. During successive runs, the men were asked to shorten their natural strides, while maintaining their pace. The scientists entered the data into computer programs that calculated just how much force was being applied to the shinbone under different striding conditions. The researchers determined that reducing stride length by about 10 percent seemed to reduce the stress on the tibia enough to lower the risk of a stress fracture.
Why, though, should shortening your stride affect your tibia at all? “Think of it this way,” says Brent Edwards, lead author of the study and now a post-doctoral research fellow in the Department of Kinesiology and Nutrition at the University of Illinois, in Chicago. “If you spend less time in the flight phase of running” — meaning in the air — “you’ll hit the ground with less force.” On the other hand, you’ll hit the ground more often. But in Mr. Edwards’s models, the reduction in pounding from an abbreviated stride outweighed the shock from a few additional strides per mile.
Even for those of us without a biomechanical expert in the house, gauging a 10 percent reduction in stride is not difficult, Mr. Edwards says. “Ten percent is about as much as you can shorten your stride without it beginning to feel quite uncomfortable,” he says. And absolute precision isn’t necessary. “Seven or eight or nine percent is fine,” he says.
Neither Ms. Petit nor Mr. Edwards suggests, of course, that any, single prevention approach will end all tibial stress fractures. “There are so many elements involved,” Ms. Petit says. Training, hormones, genetics, diet and shoe choice probably all play a role. “But if there’s something easy and benign that you can do to lessen the risk,” she asks, “why not?”
Tuesday, December 1, 2009
Saturday, November 28, 2009
Enclosed interview with Dr. Ashis Roy, who will be running his 100th marathon in Mumbai 2010. A few gems from him:
"Running is for us what flying is for birds. It builds fundamental strength. It involves every part of your body, your heart, your brain, your blood circulation."
"Running is never a problem if you take care of yourself and if you are properly hydrated."
Dr. Roy started running marathons only at the age of 52.
Thursday, November 26, 2009
Phys Ed: How Necessary Is Stretching?
By GRETCHEN REYNOLDS
For research published earlier this year, physiologists at Nebraska Wesleyan University had distance-running members of the school’s track and field team sit on the ground, legs stretched before them, feet pressed firmly up against a box; then the runners, both men and women, bent forward, reaching as far as they could past their toes. This is the classic sit-and-reach test, a well-established measurement of hamstring flexibility. The runners, as a group, didn’t have exceptional elasticity, although this varied from person to person.
Overall, the women were more supple, as might have been expected. Far more telling was the correlation between the various runners’ tight or loose hamstring muscles and their running economy, a measure of how much oxygen they used while striding. Economy is often cited as one of the factors that divide great runners from merely fast ones. Kenyan distance runners, for instance, have been found to be significantly more economical in their running than comparable Western elites.
When the Nebraska Wesleyan researchers compared the runners’ sit-and-reach scores to the measurements of their economy, which had been garnered from a treadmill test, they found that, across the board, the tightest runners were the most economical. This was true throughout the groups and within the genders. The inflexible men were more economical than the women, and for both men and women, those with the tightest hamstrings had the best running economy. They also typically had the fastest 10-kilometer race times. Probably, the researchers concluded, tighter muscles allow “for greater elastic energy storage and use” during each stride. Inflexibility, in other words, seems to make running easier.
For years, flexibility has been widely considered a cornerstone of health and fitness. Many of us stretch before or after every workout and fret if we can’t lean over and touch our toes. We gape enviously at yogis wrapping their legs around their ears. “It’s been drummed into people that they should stretch, stretch, stretch — that they have to be flexible,” says Dr. Duane Knudson, professor of biomechanics at Texas State University in San Marcos, who has extensively studied flexibility and muscle response. “But there’s not much scientific support for that.”
In fact, the latest science suggests that extremely loose muscles and tendons are generally unnecessary (unless you aspire to join a gymnastics squad), may be undesirable and are, for the most part, unachievable, anyway. “To a large degree, flexibility is genetic,” says Dr. Malachy McHugh, the director of research for the Nicholas Institute of Sports Medicine and Athletic Trauma at Lenox Hill Hospital in New York and an expert on flexibility. You’re born stretchy or not. “Some small portion” of each person’s flexibility “is adaptable,” McHugh adds, “but it takes a long time and a lot of work to get even that small adaptation. It’s a bit depressing, really.”
What happens to our muscles and tendons, then, when we dutifully stretch before a run or other workout? Doesn’t this lengthen our muscles, increasing our flexibility and range of motion?
According to the science, the answer appears to be no. “There are two elements” involved in stretching a muscle, Dr. McHugh says. One is the muscle itself. The other is the mind, which sends various messages to the muscles and tendons telling them how to respond to your stretching when the discomfort of the stretching becomes too much. What changes as you stretch a muscle is primarily the message, not the physical structure of the muscle. “You’ll start to develop a tolerance” for the discomfort of the stretch, Dr. McHugh says. Your brain will allow you to hold the stretch longer. But the muscles and tendons themselves will not have changed much. You will feel less tight. But even this sensation of elasticity is short-lived, Dr. McHugh says. In a new review article of the effects of stretching that he co-wrote and that will be published soon in The Scandinavian Journal of Medicine and Science in Sports, he looked at the measurable impacts of a number of different stretching regimens. What he found was that when people performed four 90-second stretches of their hamstrings, their “passive resistance” to the stretching decreased by about 18 percent — they felt much looser — but the effect had passed in less than an hour. To achieve a longer-lasting impact, and to stretch all of the muscles involved in running or other sports, he says, would probably require as much as an hour of concerted stretching. “And the effects still wouldn’t be permanent,” he says. “You only see changes” in the actual, physical structure of the muscles “after months of stretching, for hours at a time. Most people aren’t going to do that.”
And most of us don’t need to. “Flexibility is a functional thing,” Dr. Knudson says. “You only need enough range of motion in your joints to avoid injury. More is not necessarily better.” For runners, extremely tight hamstrings and joints have been found in some studies (but not all studies) to contribute to overuse injuries. But somewhat tight hamstrings, as the Nebraska Wesleyan study showed, can make you more economical. Some degree of inflexibility may make you a better runner.
How then to judge your own flexibility? “The sit-and-reach test is pretty good” for at-home evaluations, Dr. Knudson says, at least of your back and hamstring muscles. Using a staircase, sit and straighten your legs so that your feet push against the bottom step, toes upright. Stretch forward. “Try to lay your chest onto your thighs,” he says. If you can reach past your toes, you’re more than flexible enough. (No one yet has devised a way to reduce flexibility, by the way, although some Olympic-level coaches in other countries are rumored to be trying.)
If, on the other hand, “you can’t get anywhere near your toes, and the lower part of your back is practically pointing backward” as you reach, then you might need to try to increase your hamstring flexibility, Dr. Knudson says, to avoid injuring yourself while running, cycling or otherwise exercising. You can find multiple hamstring stretches on YouTube, although you should consult with a physical therapist before replicating them at home; proper technique is important to avoid injury. “You won’t get a lot of change,” Dr. Knudson says, ” but a little may be all you need.”
Tuesday, November 24, 2009
Sunday, November 22, 2009
Thursday, November 12, 2009
Tuesday, November 10, 2009
Jeremy Morris, a pioneer of the aerobics movement and who proved exercise is heart-healthy, dies at 99½
Jeremy Morris, Who Proved Exercise Is Heart-Healthy, Dies at 99½
Jeremy N. Morris, a British epidemiologist whose comparison of heart-attack rates among double-decker bus drivers and conductors in London in the late 1940s and early ’50s laid the scientific groundwork for the modern aerobics movement, died Oct. 28 in Hampstead, London. He was 99 ½.
“He always insisted on adding the ½,” said his daughter, Julie Zalewska.
The cause of death, she said, was pneumonia and kidney failure.
It had long been surmised that exercise and a healthy heart were correlated.
“You can go back to ancient physicians and philosophers like Hippocrates and Siddhartha who said exercise is good for you, but they didn’t have any data,” Steven N. Blair, a professor of exercise science and epidemiology at the University of South Carolina, said in an interview on Thursday. “Jerry was the guy who did the systematic research that invented the whole field of physical activity epidemiology.”
“His impact was huge,” Dr. Blair added.
Terence Kavanagh, an internist and professor of exercise science at the University of Toronto, agreed, saying, “The work he did set the tone for future research.”
Dr. Morris surmised that the proof could be found on the stairs of those double-decker buses. In 1949, he began tracing the heart-attack rates of hundreds of drivers and conductors. The drivers sat for 90 percent of their shifts; the conductors climbed about 600 stairs each working day. Dr. Morris’s data, published in 1953, indicated that the conductors had fewer than half the heart attacks of their sedentary colleagues.
In a follow-up study, Dr. Morris found that a lower incidence of heart attack among people doing physical work was not, for the most part, related to other factors, like body type. Transport for London, the city’s transportation agency, provided him with the sizes of the trousers it supplied to its workers. His data indicated that the conductors’ waistbands were smaller, but that their protection against heart attack could not be explained by their relative leanness. They had a lower risk of heart attack whether they were slim, average size or portly.
To corroborate his findings further, Dr. Morris did a study of postal workers. Comparing those who delivered the mail by walking or riding bicycles with the clerks behind the window at the post office and the telephone operators, he found that the deliverers also had a far lower risk of heart attack.
Then, in the 1960s, Dr. Morris conducted an eight-year study of the overall physical activity of 18,000 men in sedentary civil service jobs. The data showed that those who engaged in regular aerobic exercise — fast walking, cycling, swimming or other sports — reduced their risk of heart attack by half.
In 1972, in Atlanta, Dr. Morris and Dr. Ralph S. Paffenbarger Jr. were awarded the first International Olympic Committee Medal in sports science.
Jeremy Noah Morris was born in Liverpool on May 6, 1910, into a family of Jewish immigrants who had fled pogroms in eastern Poland. His father, Nathan, was a Hebrew scholar. After arriving in England, the family took the last name of the captain of the ship that had brought them to Liverpool. Jeremy was born within weeks of the arrival. The family then moved to Glasgow.
Jeremy began to exercise early in childhood. His father would take him on four-mile walks, then reward him with ice cream.
After attending the University of Glasgow, Dr. Morris completed his medical degree at University College London Hospital in 1934. In World War II, he served in India and Burma with the Royal Army Medical Corps, rising to lieutenant colonel. In 1948, he was appointed director of the social medicine division of the government-financed Medical Research Council. There he began his studies of exercise and heart risk.
Dr. Morris’s wife of 58 years, the former Galia Schuchalter, died in 1997. Besides his daughter, he is survived by a son, David; two grandchildren; and one great-granddaughter.
The studies that Dr. Morris started 60 years ago not only showed that those who exercised reduced the risk of heart attack but promoted the concept that those who had had a heart attack should exercise, said Dr. Kavanagh, the exercise science professor at the University of Toronto.
In 1973, seven heart-attack and bypass patients who had been rehabilitated by Dr. Kavanagh and his colleagues ran the Boston Marathon. Twelve years later, 20 other patients, including one with a transplanted heart, ran the marathon.
“Back in the ’60s and ’70s, once you had a heart attack you were sidelined; people thought your life expectancy was limited,” Dr. Kavanagh said. That changed, he said, because of the work of Dr. Morris and Dr. Paffenbarger, who did follow-up studies of longshoremen in Los Angeles. (Dr. Paffenbarger died in 2007.)
“Without their work we wouldn’t have had the groundwork to show that heart patients who exercise are less likely to have another attack,” Dr. Kavanagh said. “Those patients are no longer considered invalids.”
Almost every day, well into his mid-90s, Dr. Morris swam, pedaled his exercise bike or walked for at least half an hour.
Sunday, November 8, 2009
Saturday, November 7, 2009
I did a speed interval on Thursday, 5th November. I located a dirt track a little away from my house which had a 200 metre track with a 100 metre loop jutting out on one side, which made it a 300 metres loop for me, I did a warm up of about 5 rounds and then 4 into 800 metres (2 loops of 300 metres and one loop of 200m) interspersed with easy jog for 200 metres in between and followed it up with a 800 metres easy jog to finish it. I got quite ragged in the end, when i was sprinting away in the last section. being a first experience for me, i think i did okay. Track measurement may not have been exactly accurate, but the interval work out was achieved. Yes, i did some stretching after the initial easy run and in the end.
Sunday, October 25, 2009
Thursday, October 22, 2009
MONDAY, NOVEMBER 05, 2007
Sudden death during exercise - What does it mean for YOU?
Over the last few days, the world of sport and running in particular have been dominated by the New York Marathon, and the untimely and sad death of Ryan Shay, an elite marathon runner from the USA, during his country's Olympic Trials. Whenever a healthy and fit athlete dies during competition, we sit up and take notice, and the spotlight is turned away from the likes of Paula Radcliffe and Martin Lel, placed instead on the unanswerable questions of why people should die doing an activity that is supposed to be healthy?
And of course, it affects every one of us, and at The Science of Sport, as we've tried to bring you insights on these events this year, we've received questions and come across numerous discussion threads from people wondering just what to do with the knowledge that it seems anyone can be affected.
A bad year for perceptions of exercise
And let's face it - it's been a bad year. The Science of Sport was "born" in April, and already this year, we've seen:
• The collapse of former marathon great Alberto Salazar during a training run, with what was later confirmed as a heart attack brought on by coronary artery disease
• The death of two runners during the Comrades Ultramarathon in South Africa, from cardiac arrest
• The collapse and death of a 22-year old professional soccer player in Spain, Antonio Puerta, during a televised match in the Spanish Premier League. This death sent the nation into mourning, with pictures of the funeral, silences observed across the country, and FIFA calling for mandatory tests of all players
• The death of a 35-year old policeman, Chad Schieber, during the Chicago Marathon a month ago. His death was initially blamed on the heat, but later reports indicated that there was no evidence for heat stroke, or dehydration. Instead, he had a condition known as Mitral Valve Prolapse, which we discussed in a post at the time.
• The latest sad event, the death of an elite level marathon runner, Ryan Shay, in this weekend's US Olympic Trial marathon. The autopsy result is inconclusive at this early stage, though we did discuss some of the possible causes in a post on Saturday.
So it's been a bad year, and this does not count a few other, "lower profile" cases that we haven't delved into in great detail. But what do we make of this? And how should we respond? A few of our readers have asked this question, many have even been diagnosed with some of the conditions that have been implicated in some of these deaths, and understandably, there's a great deal of anxiety over just how safe exercise is, given that these healthy, fit individuals collapse and die during exercise?
The first and most important point - if you exercise, you're better off
Perhaps at the outset, we must emphasize this vital point - people who exercise and are fitter are LESS likely to suffer from cardiovascular disease and die suddenly than people who do not. In otherwords, put simply, if you took a random sample of say 1000 people, those who are fit and who exercise stand a better chance of being healthy than those who do not. Unfortunately, when athletes collapse and die, it tends to be a highly public event, and gains a disproportionate level of media attention. In these individuals, there is almost always some underlying pathology, and it is the actual act of doing exercise that places the stress on the system to cause the problem. That is, they are more likely to experience a heart attack or cardiac arrest during exercise, but their overall chances of this happening are still lower than for the inactive population.
Therefore, we cannot over emphasize this truth - regular exercise protects the heart. It increases your HDL (good cholesterol), improves cardiac function, and increases life expectancy and quality of life. Therefore, the benefits of regular exercise deserve to be acknowledged, or at the very least, held up in the debate - exercise is not dangerous, it's highly beneficial and that should never be forgotten.
Sudden cardiac death - a rare event
Now, we cannot deny, in the light of the last few months' events, that sudden death is a problem during exercise. As we mentioned in our post on the weekend, the largest available studies have estimated that the incidence of Sudden Cardiac Death (SCD, for short) lies somewhere between 1 per 200 000 and 1 per 1 000 000 athletes per year.
Looking at the primary causes, the first 'crude' distinction can be made between athletes younger than 35 and those older than 35.
Older athletes - Coronary Artery Disease
In older athletes, the primary cause of SCD is coronary artery disease. This is what caused the death of running legend Jim Fixx in 1984, and is also responsible for Salazar's collapse (read more about this condition here). It has been found to be the cause of SCD in older athletes in anything between 70% and 90% of the cases, with an estmiated incidence of 1 in 16000 runners per year. If you think about that last statistic for a second, it means that out of every 16 000 runners, 1 is likely to experience a heart attack brought on by this condition each year. If that seems high, remember the very important point that these people are still at lower risk than they would be as a result of being inactive. In fact, the correct use of exercise is a recommended form of treatment for people who have CAD, and so rather than avoid exercise, these people should embrace it as a means to overcome the problem! Obviously, it does require sensible exercise and should be supervised or cleared by a physician first.
Younger athletes - a multitude of possibilities
In younger athletes, the possibilities are slighty more numerous and include Hypertrophic Cardiomyopathy and Coronary Artery abnormalities, which we described in more detail in a previous post. So we won't go into them in too much detail here, but rather focus on what you can do to minimize risk as one of those athletes who may be diagnosed with any of these conditions.
So what do YOU do if you think you're at risk, or are concerned about SCD during exercise?
First point - education. It's vital that you educate yourself and learn about the symptoms and signs of the condition. As we emphasized, in 21% of the reported cases of HCM, there were indications of a problem before the event. Things like fainting, shortness of breath, chest pains, dizziness, all reported retrospectively by family and friends. Similarly, in 30% of cases of Coronary Artery abnormalities, symptoms were present, but ignored.
So it is vital that you understand and recognize the symptoms. All too often, the first clinical manifestation of an underlying condition is death - this is not because it happens as a bolt from the blue - it was there, but went unrecognized. So rule number one - empower yourself through knowledge.
Second point - testing and screening. OK, things get a little bit hazy here, because:
• Often, these conditions are difficult to detect, and;
• Once detected, there's no guarantee that they will be clinically significant or limit exercise in any way.
In fact, it's been shown that there is generally an unfavourable cost-benefit ratio to doing this kind of mass, specialised testing, though understandably, every individual would not consider this relevant if it meant saving ONE life (Economics is great in that it reduces the whole down to one ratio and then decides its not beneficial!) But the point is, it's hit-and-miss as to whether you can adequately detect a condition AND predict its clinical outcome. On top of this, the incidence of death is SO SMALL, it actually doesn't pay to worry excessively about trying to pick up.
One condition that jumps to mind is Wolff-Parkinson-White syndrome - it happens in about 0.15% of the population, and the risk of sudden death, even in this small group, is only 0.1%! So once you've detected it, what do you do with that information? Do you tell an athlete to avoid exercise because there's a 0.1% chance of SCD? Because remember, by denying the athlete exercise, he INCREASES his risk of disease and death in all other areas...
Example of Mitral valve prolapse - education and knowledge are the key
Take the example of Mitral valve prolapse. It is a condition that has been found to occur in 2% of the population (some studies say it's as high as 5%). Therefore, in a field of 35000 runners in Chicago and 40000 runners in New York, there could be about 1500 runners with the condition (assuming they're unique and that they are representative of the population - big assumptions, I realise, but it's to make a point!).
Add to that the 15 000 other runners who don't do the marathon but stick to three or four weekly 5 mile jogs, and suddenly you see that a vast number of people are exercising with the condition. Yet only one death happened - that of Chad Schieber, and that's not even conclusively proven as due to the condition. So what you have is a condition that CAN increase your risk of SCD during exercise, but the risk is so small, and if you combine this with a screening procedure, and knowledge of the symptoms, then you are pretty much empowered to control that risk.
Obviously the severity or the degree to which the condition affects the function of the heart varies, but that's picked up in the symptoms and screenings - the degree of mitral valve regurgitation, for example, is important. But it does emphasize the point - empower yourself through knowledge, and test yourself through medical science, and you can control the risk as much as possible.
If you do this, and pay close attention to your symptoms, then as we've said, you do everything possible. Of course, we can never provide a guarantee that you'll be OK and nothing could happen - no doctor could even provide that, and we are not cardiologists! So we don't wish to propogate the myth that a few tests and some knowledge is all it takes. But what we are saying is that regular monitoring, awareness, and knowledge will go a long way to ensuring that you exercise safely. And ultimately, that's all you can do. That, and exercise with the knowledge that your training is lowering your risk in every area compared to those people who are not training. But remember, be safe rather than sorry, and make sure!
Ross & Jonathan
POSTED BY ROSS TUCKER AND JONATHAN DUGAS ON 11/05/2007 06:37:00 AM
LABELS: EXERCISE PHYSIOLOGY, SPORTS MEDICINE
Shop Fitness said...
I have been close to individuals who have literally died during exercise. I appreciate this article, thank you.
06 NOVEMBER 2007 2:20 PM
Ross Tucker and Jonathan Dugas said...
Hi Shop Fitness, and thanks for visiting us here at The Science of Sport.
We are sorry to hear that you have known people who havedied during exercise, but at the same time we are really pleased that you could get something from this post. We really hope it helps you understand better the sudden death and exercise issue.
06 NOVEMBER 2007 4:30 PM
Alex Battisti said...
people who exercise and are fitter are LESS likely to suffer from cardiovascular disease and die suddenly than people who do not.
Exercise and 'being fit' is not equal to long distance running, where AFAIK most (relative to the number of participants) incidents of sudden death are reported. Meaning that it is not possible to infer from weightlifters and volleyballers and sprinters and wrestlers and gymnasts and runners and 'everybody else' on average being less likely to suffer from cardiovascular disease, that long distance running gives you a better 'overall health lookout'.
the incidence of Sudden Cardiac Death (SCD, for short) lies somewhere between 1 per 200 000 and 1 per 1 000 000 athletes per year.
If you're referring to the "Lausanne Recommendations" (PMID: 17143117) you should mention, that: "the incidence [of SCD] is higher in athletes (approximately 2/100,000 per year) than in non-athletes (2.5 : 1)" and that: "SCD was reported in almost all sports; most frequently involved were soccer (30%), basketball (25%) and running (15%)". Considering that there are probably (significantly) more soccer and basketball athletes (under the age of 35) than there are runners, it is a bit of a stretch (at least form this data) to say that the benefits of long distance running outweigh it's risk. Just to clear, I am not saying it does not, just that you can't conclude anything (in favor of running) from this data.
For competitive long distance running there is also the: "Sudden death during mass running events in Switzerland 1978-1987" study (PMID: 2655076). Which shows that: "The Swiss incidence of sudden cardiac death during organized mass runs was 50 to 1000 times higher than the incidence expected by chance alone (as estimated from national death register data)" and "This study confirms that there is probably a clearly increased risk of sudden death during running events with a competitive character, but this acute elevation of risk should probably not be overstated in view of both its very low population..."
So I would think you should (more) clearly differentiate between the risks of 'exercise in general' and competitive long distance running. As I can see it, the former has good favorable evidence, while the latter, well, is at least 'undecided', but (IMHO) probably more on the risky side of life.
Sunday, October 18, 2009
MY husband and I were riding our bikes not long ago, and when we were about a mile from home, we did our usual thing. We call it the sprint to the finish: ride as hard and as fast as we can until we reach our driveway, racing to see who could get there first.
We pulled up, slammed on our brakes and hopped off our bikes. A neighbor was walking by and said, "How did you do that?"
"I just put on my brakes," I told him. No, he said, he meant how could we just stop like that without cooling down?
Strange as it might seem, that had never occurred to me. But the cool-down is enshrined in training lore. It's in physiology textbooks, personal trainers often insist on it, fitness magazines tell you that you must do it — and some exercise equipment at gyms automatically includes it. You punch in the time you want to work out on the machine and when your time is up, the machine automatically reduces the workload and continues for five minutes so you can cool down.
The problem, says Hirofumi Tanaka, an exercise physiologist at the University of Texas, Austin, is that there is pretty much no science behind the cool-down advice.
The cool-down, Dr. Tanaka said, "is an understudied topic."
"Everyone thinks it's an established fact," he added, "so they don't study it."
It's not even clear what a cool-down is supposed to be. Some say you just have to keep moving for a few minutes — walking to your car after you finish a run rather than stopping abruptly and standing there. Others say you have to spend 5 to 10 minutes doing the same exercise, only slowly. Jog after your run, then transition into a walk. Still others say that a cool-down should include stretching.
And it's not clear what the cool-down is supposed to do. Some say it alleviates muscle soreness. Others say it prevents muscle tightness or relieves strain on the heart.
Exercise researchers say there is only one agreed-on fact about the possible risk of suddenly stopping intense exercise. When you exercise hard, the blood vessels in your legs are expanded to send more blood to your legs and feet. And your heart is pumping fast. If you suddenly stop, your heart slows down, your blood is pooled in your legs and feet, and you can feel dizzy, even pass out.
The best athletes are most vulnerable, said Dr. Paul Thompson, a cardiologist and marathon runner who is an exercise researcher at Hartford Hospital in Connecticut.
"If you are well trained, your heart rate is slow already, and it slows down even faster with exercise," he said. "Also, there are bigger veins with a large capacity to pool blood in your legs."
That effect can also be deleterious for someone with heart disease, said Carl Foster, an exercise physiologist at the University of Wisconsin-La Crosse, because blood vessels leading to the heart are already narrowed, making it hard for blood to get in. "That's always a concern," Dr. Foster said. "But to my knowledge there is not a wealth of experimental data."
But does it matter for the ordinary, average athlete? "Probably not a great deal," Dr. Thompson said. And, anyway, most people don't just stand there, stock still, when their workout is over. They walk to the locker room or to their house or car, getting the cool-down benefit without officially "cooling down."
The idea of the cool-down seems to have originated with a popular theory — now known to be wrong — that muscles become sore after exercise because they accumulate lactic acid. In fact, lactic acid is a fuel. It's good to generate lactic acid, it's a normal part of exercise, and it has nothing to do with muscle soreness. But the lactic acid theory led to the notion that by slowly reducing the intensity of your workout you can give lactic acid a chance to dissipate.
Yet, Dr. Foster said, even though scientists know the lactic acid theory is wrong, it remains entrenched in the public's mind.
"It's an idea we can't get rid of," he said.
In fact, Dr. Tanaka said, one study of cyclists concluded that because lactic acid is good, it is better not to cool down after intense exercise. Lactic acid was turned back into glycogen, a muscle fuel, when cyclists simply stopped. When they cooled down, it was wasted, used up to fuel their muscles.
As far as muscle soreness goes, cooling down doesn't do anything to alleviate it, Dr. Tanaka said. And there is no physiological reason why it should.
That's also the conclusion of a study of muscle soreness by South African researchers who asked 52 healthy adults to walk backward downhill on a treadmill for 30 minutes — an exercise that can cause sore leg muscles. The participants were randomly assigned to cool down by walking slowly uphill for 10 minutes or simply to stop exercising. The result, the researchers reported, was that cooling down did nothing to prevent sore muscles.
And muscle tightness?
"In a different generation we would have called it an old wives' tale," Dr. Foster said. "Now I guess I'd call it an old physiologists' tale. There are no data to support the idea that a cool-down helps." But, he added, once again, "it's an idea we can't get rid of."
Exercise researchers say they act on their own advice.
Dr. Thompson says if he is doing a really hard track workout he will jog for a short distance when he finishes to avoid becoming dizzy. If he runs a half marathon, he will "start shuffling forward," after he crosses the finish line, for the same reason.
As for Dr. Tanaka, he does not cool down at all. He's a soccer player and, he says, he sees no particular reason to do anything after exercising other than just stop.