We all know that being physically activity is good for you — good for your weight, good for your overall health, good for your mood, and good as a way to get around. But recent research suggests that bicycling is particularly good — even better than other forms of physical activity. This is important because, other than public transportation — whose routes are limited and expansion is very expensive — cycling is the only real large-scale alternative to cars for short, every-day trips and commutes. It is also important because it means that we need to be prioritizing bike facilities in every transportation plan and road design.
Being physically active provides a body-full of benefits beyond weight control. From stronger hearts and bones to better sleep and digestion, from lower blood pressure and risk of strokes to reduced chances of depression and even dementia. Many of these benefits come from relatively small moves away from the typical American’s sedentary lifestyle – walking to visit nearby friends and local stores instead of driving, taking the stairs instead of the elevator, parking at the far end of the lot rather than right in front of your destination. It is wonderful to feel fit no matter what your weight.
But overweight is a major problem. It is associated with increased rates of heart disease, high blood pressure, stroke, diabetes, certain types of cancer, gout (joint pain caused by excess uric acid), gallbladder disease as well as elevated levels of cholesterol and triglyceride (blood fat). Being overweight can also cause problems such as sleep apnea (interrupted breathing during sleep) and osteoarthritis (wearing away of the joints). There is some indication that overweight women are less likely to conceive than those with a healthy weight. Partly because of widespread cultural prejudices, obesity may contribute to a sense of failure, general unhappiness, stress, insecurity, low self esteem, embarrassment and loneliness.
It’s not a pretty picture, especially when you realize that nearly 60% of the US population is overweight, many of those are obese, and overweight is about to pass smoking as the number-one cause of preventable death in this country.
Can stepping up your level of physical activity make you loose weight? Probably not by itself – the major tool for weight reduction is reducing the number of calories in your diet. A study by Harvard School of Public Health researchers published recently in the Journal of the American Medical Association followed over 34,000 women for about 13 years all of whom were eating a typical American diet. The average weight gain was about 6 pounds. It turned out that the only people who did not gain much weight over the years were those who had a healthy weight to begin with (BMI < 25) and who did moderate-intensity activity for about an hour on most days. In other words, it’s extremely hard to permanently loose weight once you’ve put it on. (“Physical Activity and Weight Gain Prevention,” I-Min Lee, Luc Djousse, Howeard Sesso, Lu Wang, Julie Buring; JAMA, 6/2010)
But exercise can reinforce the impact of your new menu. It can help you loose weight, and — more importantly – it can help you keep from regaining lost weight. We need help because through most of human evolution the major nutritional problem was starvation, so our hormonal system does it’s best to keep us from wasting away. If we’ve spent a while walking around with an extra 20 pounds our bodies take this weight as its “set point.” If we suddenly drop those pounds, our body desperately tries to protect us by quickly creating and storing as much fat as possible in order to return us to “normal.”
What we need to do it create a new set point – and exercise is key to doing that (assuming, of course, that we also stay in control of the calories we’re eating). Even though exercise plays a secondary role to diet in loosing weight, it has a primary – or at least equal – role in keeping the lost weight off: increasing your level of physical activity helps your body settle down around a new, lower “normal weight” set-point.
Another Harvard team found that women who had recently lost weight who then did at least some jogging or running a day were much less likely to gain it back than if they were sedentary – or even if they did brisk walking. And the heavier the person was to start with, the more beneficial the exercise. (“Physical Activity in Relation to Long-term Weight Maintenance After Intentional Weight Loss in Premenopausal Women,” by Rania A. Mekary, Diane Feskanich, Frank B. Hu, Walter C. Willett, and Alison E. Field in Obesity, 6/09)
It makes sense that more intense activity has greater benefit. But where does bicycling fit in? What if you regularly ride a bike to do errands, visit friends, commute to work, and have fun — in other words, be an ordinary person doing ordinary things as part of an ordinary day? This type of functional cycling has the huge advantage of not being an “extra” that you have to find time to do after your regular tasks – it is built in to the normal unfolding of your day. It seems possible – even likely – that regular cycling will provide the same weight control benefits as explicit exercise.
A recent 14-year study of over 30,000 people in Amsterdam revealed that that people who commute by bicycle have better long-term health than those who focus on other forms of exercise, even those who exercise or play sports at a high level of intensity — simply cycling to work lowered the risk of death by 40%. The reason for the difference isn’t totally clear, but maybe it’s because doing something nearly every day has the most positive impact. Or maybe it’s got something to do with the nature of bicycling riding, which almost all cyclists agree improves your mood as well as your muscle tone. (“All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work”, by Andersen, L.B., et al., 2000, Archives of Internal Medicine, 160(11): p. 1621-1628.)
Nearly half of daily trips by American adults cover less than 3 miles. Over a quarter are less than one mile long. These are easily bike-able distances for ordinary people, although they are probably too far for most people to walk. It is the bicycle that is most able to replace the car for everyday short trips.
In addition to its health benefits, bicycling saves people money and (especially in urban areas) often takes less time than driving followed by endless circling the block looking for a parking space then walking all the way back to the destination. And bicycling benefits society as well as individuals. The more people who bike the fewer cars are on the road, reducing congestion and climate-endangering emissions, improving air and water quality, increasing the number of “eyes on the street” (the best known crime deterrent) as well as the opportunity for neighbors to interact and strengthen social ties. Not to mention that people who shop by bike are more likely to patronize local stores.
So how do we make bicycling mainstream? The reason most people give for staying off the roads is not lack of interest or low levels of physical fitness. It’s fear of traffic. Most people are, reasonably enough, afraid of getting hit by a car. The solution is rather straightforward: keep the two types of vehicles separate from each other with off-road bike paths, protected bike lanes (aka “cycle tracks”), even well-designed regular bike lanes. Experience in cities around the world show that installing any of these sparks immediate and significant increases in bike ridership – as much because they make people feel safer as because the accident rate actually goes down. And the more people who bicycle the more that car drivers get used to their presence and begin to drive more carefully when near a bicyclist.
Road surface is a scarce resource, especially in older cities. But over the past 25 years, European cities have found ways to slowly shift the balance of space from car-serving uses to bicycling. It takes vision and political will. But it can be done.