The growing interest in biking for health and commuting has had a surprising downsize: The number of bicycle accidents is rising, with many serious injuries occurring among riders older than 45 in recent years.

That’s the upshot of new research by the University of California-San Francisco that found the rate of hospital admissions associated with bicycle injuries has more than doubled since 1998, especially with head and torso injuries.

The findings, published in the Journal of the American Medical Association, are based on an analysis of a national injury surveillance database that found:

• The proportion of injuries occurring to riders above age 45 rose 81 percent, from 23 percent to 42 percent.
• Hospital admissions of older riders increased 66 percent, from 39 percent to 65 percent.
• The percentage of cyclists with head injuries rose from 10 percent to 16 percent.
• Approximately two thirds of the injuries occurred among men.

"These injuries were not only bad enough to bring riders to the emergency room, but the patients had to be admitted for further care," said Benjamin Breyer, M.D., associate professor of urology at UCSF and chief of urology at UCSF partner hospital San Francisco General Hospital and Trauma Center.

"If you take typical 25-year-olds and 60-year-olds, if they have a similar crash, it's more likely the older person will have more severe injuries."

Urban cycling has become increasingly popular in recent years for recreation and work, the researchers noted.

The researchers said their findings highlight the need for more safe riding practices and better infrastructure to prevent cycling-related injuries.

"Bicycle riding provides a fantastic way to get exercise and it has a low impact on joints," said Dr. Breyer. "Previous research has shown it has broad health benefits with reduced mortality.

“But on a national level, we need expanded support for improving the general infrastructure for cycling, especially bike lanes. And all cyclists should be aware of the risks and take appropriate precautions such as using appropriate safety gear, including helmets, and they should follow the rules of the road."