Push Hard, Push Fast: The Science of CPR Compressions

When someone's heart stops beating, you have only about 10 minutes before brain damage becomes permanent - and every minute without CPR lowers the chance of survival by roughly 10%. The good news: your hands, pushing at the right depth and speed, can keep blood flowing until help arrives.

- The exact depth and rate recommended for adult chest compressions - Why compression quality directly affects survival odds - How to find hand placement and body position for effective compressions - What to do if you get tired mid-CPR

The American Heart Association recommends compressions at least 2 inches (5 cm) deep but no more than 2.4 inches (6 cm), at a rate of 100 to 120 compressions per minute. That's almost 2 pushes every second. A helpful trick: the beat of the song 'Stayin' Alive' by the Bee Gees is almost exactly 103 beats per minute - right in the target zone.

Place the heel of one hand on the center of the chest, between the nipples, over the lower half of the breastbone. Put your other hand on top and interlock your fingers. Keep your arms straight and your shoulders directly over your hands, using your body weight - not just your arms - to push straight down.

After each push, let the chest come all the way back up before pushing again. This is called full recoil. If you lean on the chest between compressions, the heart doesn't have time to refill with blood, and each following push moves less blood than it should.