Emma Bryce's video is a great, concise visualisation of the basic understanding of how lungs work. Taking a look at the roles of Carbon Dioxide (CO2) and Oxygen (O2) in our breathing, it prepares us well for a beginners' freediving course and may well fill in some details even for advanced freedivers.
In our Beginner's courses, we will look at this and add to it the perspective of a freediver to see how we can do amazing things with our lungs (and our brains!).
This video also shows nicely how one can present this topic in a somewhat pleasant - if very american ;-) - way.
Recommended for all freedivers from absolute beginners to Seasoned educators.