The topic of VO2 Max and how it's a great indicator for longevity has been a hot topic for a while, now, so I decided to give this book by Brady Holmer a go. The author publishes the Substack Physiologically Speaking, and has a great deal of knowledge about the intersection of sports and health.
The first 75% of this book is fairly technical stuff, and not being a science guy, I had to re-read some parts to fully understand them, but that's on me and my substandard American education. The last 25% is more about what most people are really interested in, which is how to improve your personal VO2 Max. The conclusion from the research suggests that higher intensity training (HIIT) is more effective than moderate, Zone 2 exercise in increasing your VO2 Max. Furthermore, longer training periods (4-12 weeks) of higher volume sessions (>15 minutes) of longer intervals (>2 minutes) was the gold standard of increasing VO2 Max, with the primary driver of success being the longer sessions.
I have a lot of highlights from the Kindle edition posted if anyone is interested in reading more of the protocols.
Short book, well written, and recommended to athletes and non-athletes alike.