Chicago ? There’s a reason the word “choked” is used to describe those who strike out with the bases loaded or botch closing a major deal. In a moment of crisis, when they needed it most, they forgot to breathe.

Athletes, actors and professional speakers all know that breathing is an effective, powerful performance enhancer. It’s legal, free and doesn’t require injecting artificial substances into the body. Experts tell us why and how to do it:

¢ Darts. Like a free throw in basketball, a dart throw is a high-pressure shot. Relaxing beforehand is key, said Peter Citera, president of Chicago’s Windy City Darters. Some players use breath as part of the routine: inhale, step to the line, set up shot, exhale, release dart.

World No. 1 player Phil Taylor “appears to exhale as he releases the dart and follows through,” Citera said. “The bottom line is, any technique that helps you keep your mental focus in a game of repetition such as darts will make you a better player in the long run.”

¢ Running. Chicago-area running coach Bill Leach has long taught runners to focus on the out-breath portion of the breathing cycle. “Focusing on the out-breath forces us to come back into the moment,” he said. “You’ll be astounded at the increase in aerobic function you can enjoy.”

To try it, breathe out for three steps and in for two steps while running. Be patient; it might take several months to master.

“It’s all about forcing the lower abs to initiate the pressure on the diaphragm and moving the air outward from the base of the lungs,” Leach said. What most people do is try to add a little oxygen on top of the lungs where there is very little room, he said.

¢ Public speaking. Breathing exercises can help speakers project their voice and build stamina. They also help prevent embarrassing cracking or straining.

“People need to understand that there is simply no way to have strength and conviction without breathing properly,” said Kirby Tepper from Charisma Consultants in Los Angeles.

¢ Childbirth. Lamaze classes teach expectant mothers to take deep, cleansing breaths at the beginning and end of each contraction, but any breathing technique can help control pain. Breathing is not only a good distraction; it also helps relax tight muscles that contribute to labor pain. It can reduce nausea and dizziness during delivery and help bring oxygen to the mother and baby, according to the Mayo Clinic Guide to a Healthy Pregnancy.