Attrition of skills after basic life support (BLS) training is common. Psychology studies have established that for basic memory recall tasks, spaced learning strategies improve retention. Spaced learning is often organized as a refresher or 'booster' course after initial training. This study aims to investigate if this principle holds true for BLS skills, which require rapid memory recall and efficient deployment of procedural skills while under time pressure.

Health care professionals who have not received BLS training in the 6 months leading up to the date of participation will be recruited from local health care institutions in the greater-Ottawa area. Participants will be randomized into one of three groups: early booster, late booster, or no booster (control). Currently, no booster is the educational standard. The early booster group will receive a booster at 3 weeks, the late booster at 2 months, and no booster for the control. All participants will undergo BLS training, an immediate post-test, and a retention post-test at 4 months. Post-tests involve a simulated cardiac arrest scenario. Raters will be blinded to the group allocation and simulation test order.

Inclusion Criteria:

-Healthcare professionals who interact with patients and have not received any BLS training or practice in the 6 months leading up to the date of their participation will be recruited.

Exclusion Criteria:

• under 18 years of age
• non healthcare professionals
• healthcare professionals who don't interact directly with patients
• healthcare professionals who have completed Basic Life Support training in the previous six months

Trained evaluators will rate a series of videos but will be blinded to which arm of the study participants are from.