TURNS out professional race-car drivers can run with the best of them. For the first time, researchers have measured the heart rate and oxygen consumption of drivers during high-speed sessions – and have found that their cardiovascular health equals that of premier athletes in traditional sports such as football, baseball, soccer and basketball.
The study challenges commonly held perceptions that sitting down and driving isn’t a real sport, said lead author Patrick L. Jacobs, an associate professor at Miami’s Department of Neurological Surgery.
“Those of us who work closely with professional racing drivers have, for a long time, known how severe the physical demands are to operate one of these cars competitively,” said co-author Dr Steve Olvey, medical director of the Championship Auto Racing Teams series. “Racing drivers will now be recognised in the sports world as real athletes and will be accorded the respect they deserve.”
The study examined seven professional drivers and recorded their physiological responses while maneuvering raceways at speeds of 190kph to about 300kph– roughly the same speeds as those reached during actual races. Although seven subjects sounds like a small group, researchers say only 28 drivers compete at race car driving’s top level, thus their study focused on a quarter of the available pool.
Researchers found that drivers required a great deal of physical stamina to keep their bodies centred, especially when turning corners and braking. To remain competitive, many professional drivers have strict training regimens, which include biking, running to increase endurance, and weight-lifting to provide the upper body strength necessary to handle curves and turns.
The study was published in the December issue of Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine.
For a complete picture of the sport’s demands, additional studies are needed, researchers said. They don’t fully understand the physical and psychological stresses of competition and the performance effects of high temperatures inside the driver’s compartment.
Grapes of health
AFTER scientists observed in the 1980s that French people had low rates of heart disease, probably because of their fondness for red wine, US consumers began trying to replicate that health success, known as the French paradox. That has led to interest in the chemicals found in red wine. These chemicals, called oligomeric proanthocyanidins, also are found in grape-seed extract and are available in supplement form.
Grape-seed extract is believed to be a powerful antioxidant – a substance that can neutralise free-oxygen radicals, molecules that contribute to ageing and organ damage. Some researchers believe it’s better than vitamin C or E in helping to prevent diseases such as cancer and heart disease, in which free radicals play a big role.
Grape-seed extract typically comes in 50mg capsules; adults are advised to take 150mg to 300mg a day. People allergic to grapes could have a mild reaction to the extract. The supplement also may increase the potency of the blood thinner warfarin (Coumadin).
Much of the research on grape-seed extract, attesting to its antioxidant properties, has been done in Europe. But there is little evidence it can help prevent serious diseases or mitigate the effects of ageing.
Dietary supplement makers are not required by the US government to demonstrate that their products are safe or effective. Ask your health-care provider for advice on selecting a brand.
Walk it off
MEDICAL researchers rarely advise ignoring pain, but when it comes to some types of leg pain, it just might be the healthiest path.
A team of university researchers has found that people suffering from peripheral arterial disease (PAD), a form of atherosclerosis that affects eight million to 10 million adults, should walk through discomfort instead of halting exercise. Walking improves the muscles’ ability to expand and contract, they say, helping to mitigate inflammation and enhance blood flow.
The findings could improve quality of life for those with the disease, which often leaves sufferers housebound and dependent upon others.
Peripheral arterial disease occurs when cholesterol-laden plaque accumulates in the arteries, restricting blood flow to the legs. The reduction of blood can produce leg pain, aches and fatigue.
The report, based on an analysis of more than 120 exercise studies, was published last month in the New England Journal of Medicine. “Unlike coronary artery disease patients, who should stop exercising as soon as they experience chest pain, PAD patients with cramping pain should walk until they reach a moderate level of leg pain and then continue for several minutes,” said Kerry J. Stewart, director of clinical exercise physiology at Johns Hopkins University and the study’s lead author. “After a few minutes of rest, the walking should be resumed.”
The walking cycle should be repeated until the person can walk for 50 minutes without pain, said Stewart. An exercise programme in which patients walk on a treadmill several times a week may be the best way to ease pain, Stewart said.
Leg pain associated with the disease can be “substantially” lessened by sticking to a walking routine that consists of at least three outings per week over a three month period, the study said.
Researchers added a few cautions, however. Many cardiac rehabilitation programmes (in which exercise is monitored) often won’t admit PAD patients. Patients can discuss a routine with their doctor, who, in any case, should provide medical clearance for a walking programme, Stewart said.
Without exercise, people with the condition are more likely to need surgical treatments, such as a leg artery bypass or leg angioplasty.
The downside of supplements
CONSUMERS have long been warned that dietary supplements can cause various unexpected reactions. Now a nationwide US study has found that, when side effects occur, they can be life-threatening.
In the most comprehensive look yet at the incidence of side effects from dietary supplements, American scientists have found that a third of the reported adverse reactions were deemed “significant”, a category that included heart attacks, liver failure, bleeding, seizures and death.
The findings indicate that “a substantial potential for hazard exists for some users of dietary supplements,” said Dr Mary E. Palmer, lead author of the study, which appeared in the health journal the Lancet.
In 1998, 11 US poison control centres agreed to pool their data on calls about supplements. Of 784 people complaining of symptoms, researchers decided to review the 489 cases they were reasonably sure were related to supplements, said Dr Patrick E. McKinney, a medical toxicologist at the New Mexico Poison and Drug Information Centre in Albuquerque.
Although the majority of symptoms were mild, a substantial number of people experienced moderate to severe reactions, including chest pains, irregular heartbeats, tightness in the chest and throat, trouble breathing, seizures, coma, heart attacks and death. The supplements linked most often to problems were two stimulants, ma huang, whose active ingredient is ephedra, and guarana; two botanicals normally used for their calming effects, ginseng and St John’s wort; and chromium, melatonin and zinc.
Smaller studies have linked supplements to serious health problems, but there has been no way of formally documenting and compiling reports of reactions. As a result, the US Food and Drug Administration estimates that less than 1% of adverse reactions from supplement usage are officially reported.
This research is the largest study to monitor the safety of these products, which are largely unregulated, and determine the incidence of significant side effects.
“This study gives us a better snapshot of the magnitude of the problem,” said Richard J. Ko, a study co-author and research scientist with the California Department of Health Services in Sacramento.
A supplement industry spokesman said the study’s findings highlight the few negative incidents, rather than the millions of people who take supplements with seemingly no ill effects.
“The study results should focus on the remarkable infrequency of adverse reports for these commonly used products,” said Michael McGuffin, president of the American Herbal Products Association, an industry trade group in Silver Spring, Maryland.
Still, consumers need to be wary. “Dietary supplements are considered more innocuous than prescription drugs,” said Wendy Klein-Schwartz, a pharmacist with the Maryland Poison Centre in Baltimore. “But people need to know that some of their ingredients can have serious adverse effects.” - LAT-WP
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