Given their ability to help us cover miles without requiring a spousal sag wagon, sales of pedal-assisted electric bikes have soared by 70% or more each month since spring, according to industry statistics. But their surge in use has raised a question: Does riding an e-bike count as exercise?
The answer appears to be a qualified yes, according to a recent study.
Published in July in the International Journal of Environmental Research and Public Health, it involved 101 healthy adult men and women in Hamburg, Germany, who agreed to alternate riding a standard bicycle and an e-bike over two separate two-week periods.
First, some background. E-bikes, short for electric bikes, are road or mountain bikes with an added battery-powered motor to goose pedaling power. They fall into one of three types. Class 1 bikes provide assistance while you pedal, up to a speed of 20 miles per hour. Class 2 models power your ride even if you are not pedaling, but click off at 20 mph. And Class 3 versions assist pedaling up to 28 mph.
For the study, each volunteer chose their preferred e-bike model, with most picking road bikes having top assisted speeds of about 20 mph. To compensate for the novelty factor, participants spent a couple of weeks getting used to their e-bikes before the study period. The researchers also provided their volunteers with activity monitors, heart rate monitors and a phone app on which they could record their trips, distance and how physically draining each ride had felt.
The scientists did not offer their volunteers any suggestions, however, about where, when or how often to ride, said Hedwig Stenner, a research associate at the Institute of Sports Medicine at Hannover Medical School, who led the study. The researchers wanted to see how people, on their own initiative, would use the different bikes and whether their riding would change with the e-bikes.
Electric assistance did change the riders’ habits. In general, both the men and women rode more often during the two weeks with e-bikes, averaging about five rides a week vs. three a week with standard cycles. The distances of most people’s rides did not change, however. Their rides were not lengthier on the e-bikes, but they were more frequent.
Their heart rates also differed. In general, people’s heart rates were about 8% lower when they pedaled e-bikes instead of standard ones. But they still consistently hovered within the range considered moderate exercise. As a result, during the two weeks when the volunteers rode e-bikes, they accumulated sufficient minutes of moderate physical activity to meet the standard exercise recommendation of 150 minutes of moderate activity a week.
Are they safe?
There also have been safety issues around e-bikes. Many of us have heard (sometimes apocryphal) stories about e-bike accidents, including one in which TV personality Simon Cowell fractured his back during his first ride on a new electric trail bike. Crashes were not a factor in the study. “No serious injuries were reported to us,” during the research, Stenner said.
But another study of e-bikes, which was published in December in Injury Prevention, is more cautionary. For it, researchers at New York University’s School of Medicine combed a national database of emergency room visits for information about accidents related to riding a standard bicycle, motorized scooter or an e-bike from 2000 to 2017. In general, the e-bike injuries were the most severe and likely to require hospitalization.
Why e-bikers tended to hurt themselves more seriously than other riders is not clear from the data, said Charles DiMaggio, an injury epidemiologist at NYU Langone Health, who led the new study. During the years of the study, e-bikes were something of a novelty, and the unfamiliarity with them might have been a factor.
That theory was seconded by Ian Kenny, the e-bike brand leader for Specialized, a bike company that makes electric road and mountain bikes. “E-bikes accelerate faster” than standard bikes, Kenny pointed out, and that sudden momentum can disconcert and bobble unprepared riders.
He said most new riders would benefit from some practice spins in a protected area. Look for an empty parking lot or a road with very little traffic. During these shakeout sessions, use the bicycle’s lowest assistance setting, he said.