Do you think that free diving resulted in larger lung capacity? Or that you have always had larger lung capacity, and thus enjoyed free diving more than most people?
What the article doesn't mention is most people can increase their lung capacity using several techniques like over-unders (pool drills where you swim across a pool alternating between underwater and regular),Oxygen tables, breathing patterns (think meditation), and working out while holding your breath (be careful with that one, I'd suggest just walking holding your breath first).
Can you share any good resources for training?
Breathing exercises: http://freedivingexplained.blogspot.com/2008/03/freediving-t... The "go to" forum for me: https://www.deeperblue.com/