In 1973, when 29-year-old Billie Jean King played 55-year-old former No. 1 male tennis champ, Bobby Riggs in the "Battle of the Sexes," it was her relentless stroke that defeated the blowhard hustler 6-4, 6-3, 6-3.

But medically speaking, a big stroke isn't something you want.

Nonetheless, 795,000 Americas suffer a stroke each year; 87 percent of them are ischemic, meaning blood flow to the brain is critically reduced or blocked.

The results can be devastating. Stroke is the leading cause of serious long-term disability; one in 20 U.S. adult deaths is caused by stroke.

Americans seemed to be winning the battle against stroke. The incidence was decreasing.

But now, according to the Centers for Disease Control and Prevention, that decrease is reversing in 20 states, and stalling in most others.

The reason? An alarming increase in stroke among people 35 to 44, triggered by diabetes, obesity, inactivity, elevated LDL cholesterol, untreated stress, high blood pressure and smoking.

From 2003 to 2012, hospitalization for acute ischemic stroke for that age group jumped 41.5 percent for men and 30 percent for women.

Most strokes are preventable if you: Eat 7 to 9 servings daily of produce; ditch highly processed foods, red and processed meats and anything with added sugars; learn to manage stress; and walk 10,000 steps daily.

That'll help keep LDL cholesterol in check (aim for under 100 mg/dL), help maintain a healthy weight, and help control blood pressure (aim for under 125/85).