Then-senator John F. Kerry riding his bike in Santa Fe, N.M., during the 2004 presidential campaign. Note the helmet. Photo: John Sullivan/Getty Images)

Back in May 2004, during the presidential campaign, then-President George W. Bush took a nasty spill off his mountain bike and banged up his face.

And Sen. John Kerry (D-Mass.), 71,  defeated by Bush a few months later, had this to say, according to The St. Petersburg Times: “I hope he’s okay. I didn’t know the president rode a bike.”

But Kerry, who’d also had a road (not mountain) bike accident that same month in Concord, Mass., told reporters (in what he thought was on off-the-record quip):”Did the training wheels fall off?”

This sparked something of a political brouhaha. Then-Chicago Mayor Richard M. Daley, who had ripped the skin off his knee in a bike mishap a few years earlier, had scolded Kerry: “You should not wish ill upon anyone.”

In contrast to Bush’s scrapes and bruises back then, Kerry’s possibly quite serious injury after a fall Sunday in Switzerland — a fractured femur in the same leg where he underwent hip replacement surgery in 2009 — could leave him on crutches for a while.

The duo’s various spills also point up the regularity with which prominent figures take some nasty falls off their bikes — and not just on mountain terrain. Rock star Bono, who just turned 55, had a nasty fall in November in New York’s Central Park that left him with a fracture of his left eye socket, a fractured shoulder blade and a fracture elbow which required five hours of surgery in all.

Politicians and government officials everywhere seem especially prone to these accidents. In 2012, former congressman and now Army Secretary John McHugh fractured his pelvis after swerving to avoid hitting some pedestrians  on a Northern Virginia bike path and spent three weeks rehabbing at Walter Reed Hospital.

Last year, a Canadian member of the opposition Parti Quebecois, hit a pothole while cycling in a park and suffered eight fractures, including to his collar bone, ribs and hip. His helmet was badly damaged.

So remember: always wear that helmet and be careful out there.