Dick Jensen’s gym routine in Petaluma was “do the elliptical, go to the water fountain and then go to the treadmill.”

But last January, the 66-year-old got to the water fountain and his heart suddenly stopped.

Daniel Petersen, on a nearby stationary bike, heard a bang and turned to see Jensen fall against some lockers and to the floor.

“I did a double take and realized he’s not getting up,” he said.

Petersen ran over and began pressing hard and fast on Jensen’s chest while an employee at 24 Hour Fitness called 911 and another grabbed an AED, the in-house automated external defibrillator, to shock Jensen’s heart into beating.

Jensen, now recovered from his heart attack but still nursing a smashed ankle from the fall, owes his life to quick-thinking Petersen, the gym workers and Petaluma firefighters who rushed him to Santa Rosa Memorial Hospital’s cardio center.

CPR, or cardiopulmonary resuscitation, has gotten easier. You just use your hands.

There are just three easy steps to using hands-only CPR, said Jeff Schach, battalion chief in charge of emergency medical services for the Petaluma Fire Department.

“If someone collapses, shake him and shout, ‘Are you OK?’. If there’s no response, call 911 or have someone else call. Then, start pushing down hard and fast in the center of the chest.”

Diane Aviles, 75, was carrying picnic food into the Petaluma Senior Center in June when she told a woman at the door. “I think I have a problem.” Aviles collapsed, the other woman yelled “Help!” and center director Don Streeper came running and started doing CPR.

“You react. You don’t think,” Streeper said.

Troy Wright, 50, was having coffee with his wife at their Freestone home when he felt a pain between his shoulders. His wife began to massage his back when he was hit with “a full heart attack.”

His wife and teenage son did hands-only CPR until paramedics arrived.

Hands-only CPR is a term coined by the American Heart Association as a user-friendly alternative to traditional CPR. A short how-to video is at www.heart.org/handsonlycpr, with this music tip: If you press down to the beat of the Bee Gees’ hit “Stayin’ Alive” you’ll keep the blood flowing at the ideal 100 beats a minute.

About 92 percent of sudden-cardiac-arrest victims die before reaching the hospital, according to the Heart Association, but immediate CPR can double, or even triple, a victim’s chance of survival.

Also known as compression-only CPR, it bypasses the more involved CPR that includes mouth-to-mouth resuscitation, which often keeps people from rushing to another’s aid.

People are fearful of doing mouth-to-mouth on a stranger, said Schach. They also worry about doing it wrong and hurting someone. Indeed, when you press upon a chest you may feel “bones cracking,” he said.

But, said Schach, “You really can’t do it wrong. You can’t hurt them,” he said, adding frankly, “Their heart has stopped. They’re dead.”

Good Samaritan laws, which say that you cannot be held liable if you try to help, trained or not, protect the bystander who steps in.

Hands-only CPR works to “stop the clock,” said Schach, because while emergency people may get there in three to five minutes, in that time after the heart stops, brain damage can begin.”

North Bay residents can learn hands-only CPR through Save Lives Sonoma, a coalition of health and emergency agencies who give demonstrations and classes. For events, go to www.savelivessonoma.com.

Lauri McFadden, chair of the group and operations manager at Sonoma Life Support, the ambulance company, explained the beauty of hands-only CPR.

“If I were to collapse right now, I have oxygenated blood in my body,” she said. “What I need is to keep that blood going into my brain and heart and vital organs. When your heart stops, your own pump stops, then someone else becomes the pump.”

The victim often remembers little of the drama. Jensen, who had no history of heart problems, recalls only being at the gym and then waking up in the hospital.

Wright heard his wife calling 911. “She was yelling my age and our address,” he said.

The rescuer can tell you every detail.

Melanie Wright, coached by a 911 dispatcher on how and where to push on her husband’s chest, said, “I wasn’t afraid to hurt Troy because I knew he was dying.”

For Petersen, the gym rescue was the first time he used CPR “on a real person, not a mannequin.” He took CPR after a friend collapsed in a basketball game and he “felt helpless because I couldn’t do anything.”

Fortunately a paramedic who was also playing knew CPR, but Petersen resolved “to know how to do something the next time. Because you never know.”

Susan Swartz is a freelance writer and author based in Sonoma County. Contact her at sfswartz@gmail.com.