(CBS/AP) MARICOPA, ARIZ. - The bicycle accident that took the life of 27-year-old marathoner Sally Meyerhoff is a tragic reminder of just how dangerous bicycling can be.
Meyerhoff - winner of the women's 2011 P.F. Chang's Rock 'n Roll Marathon and a qualifier for the 2012 Olympic marathon trials - died instantly on Tuesday after colliding with a truck while riding her bike here.
Such accidents are all too common. The Centers for Disease Control and Prevention says bicycle-related mishaps send more than 500,000 people each year to emergency rooms - and kill more than 700.
Helmets are one key to safe bicycling. Wearing a helmet that fits properly can cut the risk of head injuries by more than 85 percent, according to the National Traffic Safety Administration.
Want to know what else you can do to stay safe on two wheels?