Women: Ride a Bike, Prevent Weight Gain

< Jun. 30, 2010 > -- Premenopausal women can help prevent weight gain by riding a bicycle just as effectively as by walking, according to new research.

Anne C. Lusk, Ph.D., lead author of the study and a research fellow in the department of nutrition at the Harvard School of Public Health in Boston, says that biking is particularly helpful at keeping pounds off premenopausal women who are overweight or obese.

Dr. Lusk and her team reported their findings this week in the Archives of Internal Medicine.

"Women of normal body weight can certainly benefit from biking," she notes. "But specifically for overweight and obese premenopausal women, bicycling just two to three hours per week makes them 46 percent less likely to gain more than 5 percent of their initial body weight over the long run."

In addition, the researchers found that slow walking - walking less than three miles an hour - does not help control weight.

Despite Physical Activity Recommendations, Obesity Rates Increasing

According to the study authors, the US Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine recommended in 1995 that all American adults engage in a half hour a day of moderately intense activity.

Despite the advisory, two-thirds of Americans are now either overweight or obese, Dr. Lusk and her team note, while 16 percent of American children and adolescents are overweight, and one-third are at risk for gaining excess weight.

In earlier research, the study team had reported that brisk walking helped women who were at normal weight or had just lost weight to keep weight off, while slow walking showed no such benefit.

This time, the researchers decided to explore the potential health benefits that could be reaped if more women took up routine biking.

Just 0.5 percent of Americans over the age of 16 who commute to work use a bicycle. The researchers report that only 23 percent of bicycling commuters are women.

Medical history, body weight patterns, exercise habits, and general lifestyle data concerning more than 18,400 women who participated in the Nurses' Health Study II were evaluated. The study participants, all women between 25 and 42 years old in 1989, were premenopausal through 2005 and had no physical impediments to exercise.

Dr. Lusk's team focused on the weight change that occurred between 1989 and 2005.

Exercise, Weight Loss Differences

In 1989, about half the women said they had spent time walking slowly, while almost 40 percent said they walked quickly and nearly half said they had spent some time riding a bike.

By 2005, the women had gained an average of more than 20 pounds, while significantly decreasing the total amount of time they spent being active.

However, women who were not biking at the beginning of the study but who did so to some degree by 2005 experienced significantly less weight gain on average. This was especially true among women carrying excess weight, for whom biking as little as five minutes a day made a difference. The researchers found that the longer women biked, the less weight they gained.

In contrast, those who decreased bike time over the years, from under 15 minutes per day to little or no biking, saw bigger weight gains.

And normal-weight women who bicycled more than four hours a week in 2005 had lower odds of gaining more than 5 percent of their baseline body weight, the researchers found.

Ride a Bike or Walk Briskly

The team concluded that bicycling, like brisk walking, should be encouraged for premenopausal women, particularly if they are coping with weight issues.

"We're advocating for a physical activity that is a routine part of the day," Dr. Lusk says. "You don't have to think about your heart rate, how many times a week that you do it, or all of that. We're just recommending that seven days a week you put brisk walking or biking into your day."

However, Dr. Nieca Goldberg, medical director of the Women's Heart Program at New York University Medical Center in New York City, issued a cautionary note regarding how women might interpret this new information.

"I think downplaying the benefit of slow walking is a bad message to send out to people who may have spent most of their life sitting in a chair, so to speak," Dr. Goldberg says. "Because slow walking is a good starting point if you don't already walk. It's cheaper than biking, and maybe easier, and basically you have to start somewhere."

Always consult your physician for more information.

Everyday Ways to Activate Your Life

Moderately intense activities are good for your health. These are activities that make you feel some exertion but are mild enough that you can comfortably carry on a conversation while doing them. Examples include walking briskly from your parked car to the mall entrance and taking your dog for a quick jog after dinner.

This level of exercise will not help you train for a sport, but it can help you achieve and maintain a healthy weight and improve your overall fitness level. Moderate exercise can also help reduce your risk for cardiovascular disease and osteoporosis, put you in a better mood and improve your balance, coordination and agility.

You have dozens of opportunities each day to increase your activity. Here are a handful of suggestions to get you started:

• Pace when you are talking on the phone instead of staying put. Although this will not burn a lot of calories, getting out of your chair throughout the day can help improve your circulation.
• Deliver memos in person instead of having your assistant do it, sending them via interoffice mail or faxing them. Consider these excursions exercise breaks.
• Go window shopping or browsing in your spare time. Shopping is the ultimate easy walking workout. Wear athletic socks and walking shoes.
• Paint your house - you can burn an average of 300 calories an hour and get a good upper-body workout.
• Vigorous house cleaning can burn about 420 calories an hour. All of these apply: cleaning floors, vacuuming carpets, washing windows, and scrubbing tile.
• Do your own yard work and gardening. Hoeing burns about 360 calories an hour, the same as playing badminton. Cutting your lawn with a push mower burns about 420 calories an hour, on par with playing tennis. Trimming trees burns about 500 calories an hour, equivalent to swimming the crawl.
• Turn lunchtime into an exercise adventure. Rather than eating at the company cafeteria or the same old place, discover new restaurants within walking distance from your workplace.
• Park your car in the garage and leave it there if you are going anywhere less than a mile away. Taking the hilliest route possible when you are walking will burn extra calories.
• Limit sedentary activities during your leisure time. For example, turn off the television several nights a week. Without TV programs to distract you, you will move around more than you would otherwise.
• Each flight of stairs you climb burns 10 calories. That may not sound like much, but taking 10 flights a day for a year can result in a 10-pound weight loss.

Always consult your physician for more information.