CYCLING IS terrific exercise, hitting the cardiovascular system and major muscle groups simultaneously, but it may not be the best thing for building strong bones. Compared with male runners, male cyclists appear more likely to have lower-than-normal bone density.

"You would think that cyclists are very healthy, because they spend all those hours training," says Pam Hinton, associate professor of nutritional sciences at the University of Missouri-Columbia and co-author of the study accepted for publication in the journal Metabolism. "In other aspects they are — cardiovascular health and body composition. But in this one aspect, they're not doing so well."

The study tested the bone mineral density of 27 cyclists and 16 runners ages 20 to 59 who had engaged in their sport a minimum of six hours a week for at least two years. Hinton controlled for diet, past exercise and weight training. Whole body scans and blood tests showed that 63 percent of cyclists had osteopenia of the spine or hip, compared with 19 percent of the runners.

Osteopenia is bone mineral density that's lower than normal but not so low to be considered osteoporosis, or very low bone mineral density. Not all who have osteopenia will develop osteoporosis, and treatment isn't always required.

Some of those with osteopenia were in their 20s and 30s, "and that was pretty alarming to me," Hinton says.


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"I thought I'd just see it in guys who were older and had been riding for years."

In general, men may not be as much at risk for low bone density as women — especially postmenopausal women. But Hinton says they should be concerned, because osteopenia can lead to osteoporosis and injuries such as hip fractures.

Bone cells are surrounded by fluid that, when hit with an impact force, moves back and forth. That action signals to the bone cells to add more mass. "You lose bone mass quickly if there isn't some kind of mechanical loading on the bone," Hinton says.

That, she adds, best comes from movement involving impact — running, playing basketball or soccer, or doing plyometric exercises such as jumping.

Weight training also can exert force on the bone, says Hinton, but not as much as during impact, perhaps accounting for the lower bone mineral density in cyclists. Some of the study participants protested that the muscle contractions that occur when pedaling and standing on the pedals should account for some impact. "But the pedal is moving with you," she says. "You don't have the earth resisting your body."

Hinton recommends that cyclists add a little variety to their workouts to help increase bone density: running, playing basketball, jumping rope or doing plyometrics a couple times a week.

"When you're young, you should be maximizing your bone density," she says, "and as you get older, exercise slows the rate of loss. So it's really important, no matter where you are in your life, to be doing some kind of bone-loading exercise."

— Los Angeles Times

About hot tubs

What's in the water? Before you lower yourself into that steamy hot tub think twice about what's living under the surface. Hot tub "folliculitis" is an infection of the hair follicles that results from exposure to certain bacteria that live in warm, wet areas, according to the Centers for Disease Control. Pseudomonas appears as itchy bumps, sometimes filled with pus. It may then develop into dark red tender nodules. The disease usually clears on its own.

Indoor hot tub users are also vulnerable to a respiratory illness from inhaling mycobacteria, which can grow in tubs that aren't cleaned often, according to the Mayo Clinic. Symptoms include a flu-like fever and chills, shortness of breath, a dry cough, night sweats and weight loss. Treatment may include antibiotics and prednisone; some sufferers have been hospitalized.

Wannabe fathers beware: Male fertility plunges with frequent dips into a hot tub, according to a 2007 University of California-San Francisco study.

It's not all bad, though. Hot tub therapy helped a group of people with type 2 diabetes reduce their blood sugars, lose weight and improve sleep patterns in a 1999 pilot study that appeared in The New England Journal of Medicine. The participants sat in a hot tub with water as hot as 104 degrees for 30 minutes per day, six days per week, for three weeks. Researchers caution that diabetics shouldn't try this without a doctor's OK.

Along with treating common ailments such as back and joint pain, hot tub therapy has been used to treat high blood pressure. Patients are always advised to consult their doctor before trying this therapy because, initially, the therapy raises blood pressure due to increased body temperature. Hot water dilates blood vessels, and the heart does not have to work hard in pumping blood, providing relief. Whirlpools used in hospitals and medical clinics are safest.

— McClatchy Newspapers

Breaking water

Often, a pregnant woman in early labor has just been assigned a hospital bed when her doctor pops in to break her water — supposedly a way to get the show on the road. But new research suggests the procedure might do no such thing.

The hormones in the amniotic fluid have been thought to stimulate contractions, but not only does an amniotomy fail to speed up and strengthen labor, it also fails to improve a woman's satisfaction with the birth experience, an analysis by the Cochrane Review found. Nor does it result in the baby being in better condition after birth.

Lead author Rebecca Smyth of the University of Liverpool cautions that the review probably shouldn't be the final word on the common practice. Her report, published last week, analyzed 14 studies involving almost 5,000 women, but some of the research was of inferior quality. And questions remain, such as whether the stage of cervical dilatation matters in the outcome.

Still, Smyth says, pregnant women should be informed that current research suggests breaking the water has no effect. "In some centers, it is advocated and performed routinely in all women," she notes. "And in many centers, it is used for women whose labors have become prolonged."

— Los Angeles Times