(HealthDayNews) -- Experts say a bike helmet must be mandatory equipment for anyone who rides.

But the percentage of teen cyclists who wear helmets is now close to zero, the U.S. Centers for Disease Control and Prevention notes.

If every bicycle rider wore a helmet, it would prevent an estimated 150 deaths and 100,000 head injuries each year, the agency says.

Bicycle helmets reduce the risk of serious head injury by as much as 85 percent and the risk of brain injury by as much as 88 percent. Helmets also have been shown to reduce the risk of injury to the upper and mid-face by 65 percent.

So buy a properly fitted helmet and wear it whenever you ride. It's that simple.