CPR training teaches you how to keep blood and oxygen flowing to someone’s brain and organs when their heart stops, using chest compressions, rescue breaths, and an automated external defibrillator (AED). Most courses take between two and four hours and cover adults, children, and infants, though the exact curriculum depends on whether you’re taking a course designed for the general public or one aimed at healthcare professionals. Here’s what you’ll actually learn and practice.
Chest Compressions: The Core Skill
The single most important thing you’ll learn is how to deliver high-quality chest compressions. For adults, that means pushing hard and fast on the center of the chest at a rate of 100 to 120 compressions per minute, with each compression reaching a depth of at least 2 inches. For children and infants, the target depth is about one-third the depth of the chest. You’ll practice letting the chest fully recoil between compressions, which allows the heart to refill with blood.
The standard rhythm for a single rescuer is 30 compressions followed by 2 rescue breaths, then repeat. That 30:2 ratio applies to adults, children, and infants when you’re working alone. When two trained rescuers are helping a child or infant, the ratio shifts to 15 compressions and 2 breaths, which delivers more oxygen to smaller bodies that need it.
You’ll spend most of your class time on a practice manikin getting this right. Since 2019, the American Heart Association has required that all adult CPR training use feedback devices that measure your compression rate, depth, hand placement, and chest recoil in real time, giving you audio or visual cues so you can correct your technique on the spot. This is the part of training that surprises most people: effective chest compressions require more force and speed than you’d expect, and the feedback device makes that immediately clear.
Rescue Breaths and Barrier Devices
After every 30 compressions, you tilt the person’s head back, lift their chin, and deliver two breaths. Each breath should last about one second and produce a visible chest rise. You’ll practice this on manikins using a barrier device, which is a small plastic shield or pocket mask that sits over the person’s mouth. Barrier devices reduce direct contact and are standard equipment in first aid kits, though courses also teach that compression-only CPR (hands-only, no breaths) is an acceptable option for bystanders who are untrained or uncomfortable giving mouth-to-mouth to an adult.
For infants, the technique is different. You cover both the nose and mouth with your mouth and give gentler puffs of air rather than full breaths. The course walks you through these differences with separate practice sessions for each age group.
How to Use an AED
Every standard CPR course includes AED training. An AED is the portable device you’ve probably seen mounted on walls in airports, gyms, and office buildings. It analyzes a person’s heart rhythm and delivers an electric shock if needed. The steps you’ll practice follow a specific sequence:
- Power on the device. Modern AEDs walk you through every step with voice prompts once you turn them on.
- Expose the chest and attach the pads. One pad goes on the upper right chest, the other on the lower left side below the armpit. If the person’s chest is wet, you wipe it dry first.
- Clear the person. Before the AED analyzes the heart rhythm, you make sure nobody is touching the person and say “Clear!” loudly.
- Deliver a shock if prompted. The AED decides whether a shock is appropriate. You simply press the button when told to, then immediately resume compressions.
For small children, if the pads risk touching each other on a small chest, you place one pad on the center of the chest and one on the back between the shoulder blades. The course covers these variations so you’re prepared regardless of who needs help.
Choking Relief for All Age Groups
CPR training includes what to do when someone’s airway is blocked by food or a foreign object. For conscious adults and children, you’ll practice abdominal thrusts (the Heimlich maneuver), which use quick upward pressure below the ribcage to force air out of the lungs and dislodge the object. For infants, the technique switches to a combination of back blows and chest thrusts, since abdominal thrusts can injure their smaller organs.
You’ll also learn what to do if the person becomes unconscious while choking: lower them to the ground, begin CPR, and check the mouth for a visible object before giving breaths. The American Academy of Pediatrics recommends this training specifically for parents, teachers, and childcare providers, since young children are at the highest risk for choking emergencies.
Team CPR and Real-World Scenarios
Courses designed for healthcare professionals, known as Basic Life Support (BLS) courses, go further than lay-rescuer classes. BLS training covers how to function as part of a team during a resuscitation, including role assignments, communication, and smooth transitions between rescuers so compressions never stop for more than a few seconds. This team-based approach reflects what actually happens in hospitals and ambulances.
Lay-rescuer courses (often called Heartsaver courses) focus more on what a single bystander should do: recognizing cardiac arrest, calling 911, starting compressions, and using an AED until paramedics arrive. Both course levels teach the “Chain of Survival” concept, which is the idea that each link, from early recognition to early defibrillation to professional medical care, dramatically improves the person’s chances.
Course Formats and Time Commitment
You can take CPR training in two main formats. A fully in-person class runs about two to four hours depending on the provider and course level. A blended option lets you complete the knowledge portion online at your own pace, then attend a shorter in-person skills session where you demonstrate compressions, breaths, AED use, choking relief, and other hands-on skills with an instructor. After finishing the online portion, you typically have up to 90 days to complete the skills session.
Both the American Heart Association and the American Red Cross offer these formats. The hands-on component is non-negotiable for certification: you need to physically demonstrate competency on a manikin, not just pass a written test.
Certification, Renewal, and Legal Protections
CPR certification is valid for two years from the date of issue. After that, you take a renewal course, which is typically shorter than the original since it focuses on refreshing skills and updating you on any guideline changes. Keeping current matters because compression techniques and protocols do get updated as new research emerges.
Most courses also briefly cover Good Samaritan laws, which exist in all 50 states. These laws protect anyone who attempts CPR in good faith during an emergency. As long as you act reasonably and without negligence, you cannot be held legally liable if the person is injured during your rescue attempt or if resuscitation is unsuccessful. Importantly, being certified does not legally obligate you to perform CPR. The protection applies whether you’re certified or not.